/*
 * Really easy field validation with Prototype
 * http://tetlaw.id.au/view/blog/really-easy-field-validation-with-prototype
 * Andrew Tetlaw
 * Version 1.5.3 (2006-07-15)
 * 
 * Copyright (c) 2006 Andrew Tetlaw
 * http://www.opensource.org/licenses/mit-license.php
 */
Validator = new Class({
	initialize: function(className, error, test, options) {
		this.options = Object.extend({}, options || {});
		this._test = test ? test : function(v,elm){ return true };
		this.error = error ? error : 'Validation failed.';
		this.className = className;
	},
	test : function(v, elm) {
		return this._test(v,elm);
	}
});

var Validation = new Class({
	initialize : function(form, options){
		this.options = Object.extend({
			onSubmit : true,
			stopOnFirst : false,
			immediate : false,
			focusOnError : true,
			useTitles : false,
			onFormValidate : function(result, form) {},
			onElementValidate : function(result, elm) {}
		}, options || {});
		this.form = $(form);
		//Garbage.collect(this.form)
		if(this.options.onSubmit) this.form.addEvent('submit',this.onSubmit.bind(this));
		if(this.options.immediate) {
			var useTitles = this.options.useTitles;
			var callback = this.options.onElementValidate;
			this.form.getElementsBySelector("input, select, textarea").each(function(input) {
				input.addEvent('blur', function(ev) { Validation.validate(new Event(ev).target,{useTitle : useTitles, onElementValidate : callback}); });
			});
		}
	},
	onSubmit :  function(ev){
		if(!this.validate()) new Event(ev).stop();
	},
	validate : function() {
		var result = false;
		var useTitles = this.options.useTitles;
		var callback = this.options.onElementValidate;
		if(this.options.stopOnFirst) {
			result = this.form.getElementsBySelector("input, select, textarea").all(function(elm) { return Validation.validate(elm,{useTitle : useTitles, onElementValidate : callback}); });
		} else {
			result = this.form.getElementsBySelector("input, select, textarea").every(function(elm) { return Validation.validate(elm,{useTitle : useTitles, onElementValidate : callback}); });
		}
		if(!result && this.options.focusOnError) {
			this.form.getElement('.validation-failed').focus()
		}
		this.options.onFormValidate(result, this.form);
		return result;
	},
	reset : function() {
		this.form.getElementsBySelector("input, select, textarea").each(Validation.reset);
	}
});
Validation = Object.extend(Validation, {
	validate : function(elm, options){
		options = Object.extend({
			useTitle : false,
			onElementValidate : function(result, elm) {}
		}, options || {});
		elm = $(elm);
		//Garbage.collect(elm);
		var cn = elm.className.split(" ");
		return result = cn.every(function(value) {
			var test = Validation.test(value,elm,options.useTitle);
			options.onElementValidate(test, elm);
			return test;
		});
	},
	test : function(name, elm, useTitle) {
		var v = Validation.get(name);
		var prop = '__advice'+name.camelCase();
		if(Validation.isVisible(elm) && !v.test($(elm).getValue(), elm)) {
			if(!elm[prop]) {
				var advice = Validation.getAdvice(name, elm);
				if(!$pick(advice, false)) {
					var errorMsg = useTitle ? ((elm && elm.title) ? elm.title : v.error) : v.error;
					advice = new Element('div').addClass('validation-advice').setProperty(
						'id','advice-'+name+'-'+Validation.getElmID(elm)).setStyle('display','none').appendText(errorMsg);
					switch (elm.type.toLowerCase()) {
						case 'checkbox':
						case 'radio':
							var p = $(elm.parentNode);
							if(p) {
								p.adopt(advice);
							} else {
								advice.injectAfter($(elm));
							}
							break;
						default:
							advice.injectAfter($(elm));
				    }
					advice = $('advice-' + name + '-' + Validation.getElmID(elm));
				}
				try {
					$(advice).setStyles({
						'display':'block',
						'visibility':'hidden'
					}).effect('opacity').start(0,1)
				} catch(e){
					$(advice).setStyle('display','block');
				}
			}
			elm[prop] = true;
			elm.removeClass('validation-passed');
			elm.addClass('validation-failed');
			return false;
		} else {
			var advice = Validation.getAdvice(name, elm);
			if(advice) advice.setStyle('display','none');
			elm[prop] = '';
			elm.removeClass('validation-failed');
			elm.addClass('validation-passed');
			return true;
		}
	},
	isVisible : function(elm) {
		while(elm.tagName != 'BODY') {
			if($(elm).getStyle('display') == "none") return false;
			elm = elm.parentNode;
		}
		return true;
	},
	getAdvice : function(name, elm) {
		var returnVal = false;
		try{
			returnVal = $('advice-' + name + '-' + Validation.getElmID(elm))
		} catch(e){}
		if(!returnVal){
			try{
				returnVal = $('advice-' + Validation.getElmID(elm))
			} catch(e){}
		}
		return returnVal;
	},
	getElmID : function(elm) {
		return elm.id ? elm.id : elm.name;
	},
	reset : function(elm) {
		elm = $(elm);
		var cn = elm.className.split(" ");
		cn.each(function(value) {
			var prop = '__advice'+value.camelCase();
			if(elm[prop]) {
				var advice = Validation.getAdvice(value, elm);
				advice.setStyle('display','none');
				elm[prop] = '';
			}
			elm.removeClassName('validation-failed');
			elm.removeClassName('validation-passed');
		});
	},
	add : function(className, error, test, options) {
		var nv = {};
		nv[className] = new Validator(className, error, test, options);
		Validation.methods = Object.extend(Validation.methods, nv);
	},
	addAllThese : function(validators) {
		var nv = {};
		$A(validators).each(function(value) {
				nv[value[0]] = new Validator(value[0], value[1], value[2], (value.length > 3 ? value[3] : {}));
			});
		Validation.methods = Object.extend(Validation.methods, nv);
	},
	get : function(name) {
		return Validation.methods[name] ? Validation.methods[name] : new Validator();
	},
	methods : {}
});

Validation.add('IsEmpty', '', function(v) {
	return  ((v == null) || (v.length == 0)); // || /^\s+$/.test(v));
});

Validation.addAllThese([
	['required', 'Dit is een verplicht veld.', function(v) {
				return !Validation.get('IsEmpty').test(v) && trim(v) != '';
			}],
	['validate-number', 'Vul een juist nummer in.', function(v) {
				return Validation.get('IsEmpty').test(v) || (!isNaN(v) && !/^\s+$/.test(v));
			}],
	['validate-digits', 'Vul alleen getallen in.', function(v) {
				return Validation.get('IsEmpty').test(v) ||  !/[^\d]/.test(v);
			}],
	['validate-alpha', 'Vul alleen letters (a-z) in.', function (v) {
				return Validation.get('IsEmpty').test(v) ||  /^[a-zA-Z]+$/.test(v);
			}],
	['validate-decimal', 'Vul een decimaal in een punt of komma is verplicht.', function (v) {
				return Validation.get('IsEmpty').test(v) ||  /^[0-9\.\,]+$/.test(v);
			}],			
	['validate-alphanum', 'Vul alleen letters (a-z) of getallen (0-9) in. Spaties en andere karakters zijn verboden.', function(v) {
				return Validation.get('IsEmpty').test(v) ||  !/\W/.test(v);
			}],
	['validate-date', 'Vul een datum in: dd-mm-yyyy. bijvoorbeeld 17-03-2006.', function(v) {
				if(Validation.get('IsEmpty').test(v)) return true;
				var regex = /^(\d{2})\-(\d{2})\-(\d{4})$/;
				if(!regex.test(v)) return false;
				var d = new Date(v.replace(regex, '$2/$1/$3'));
				return ( parseInt(RegExp.$2, 10) == (1+d.getMonth()) ) && 
							(parseInt(RegExp.$1, 10) == d.getDate()) && 
							(parseInt(RegExp.$3, 10) == d.getFullYear() );
			}],
	['validate-email', 'Vul een juist e-mailadres in. Bijvoorbeeld: fred@domain.com .', function (v) {
				return Validation.get('IsEmpty').test(v) || /\w{1,}[@][\w\-]{1,}([.]([\w\-]{1,})){1,3}$/.test(v);
			}],
	['validate-url', 'Vul een juiste url in.', function (v) {
				return Validation.get('IsEmpty').test(v) || /^(http|https|ftp):\/\/(([A-Z0-9][A-Z0-9_-]*)(\.[A-Z0-9][A-Z0-9_-]*)+)(:(\d+))?\/?/i.test(v);
			}],
	['validate-date-au', 'Please use this date format: dd/mm/yyyy. For example 17/03/2006 for the 17th of March, 2006.', function(v) {
				if(Validation.get('IsEmpty').test(v)) return true;
				var regex = /^(\d{2})\/(\d{2})\/(\d{4})$/;
				if(!regex.test(v)) return false;
				var d = new Date(v.replace(regex, '$2/$1/$3'));
				return ( parseInt(RegExp.$2, 10) == (1+d.getMonth()) ) && 
							(parseInt(RegExp.$1, 10) == d.getDate()) && 
							(parseInt(RegExp.$3, 10) == d.getFullYear() );
			}],
	['validate-currency-dollar', 'Please enter a valid $ amount. For example $100.00 .', function(v) {
				// [$]1[##][,###]+[.##]
				// [$]1###+[.##]
				// [$]0.##
				// [$].##
				return Validation.get('IsEmpty').test(v) ||  /^\$?\-?([1-9]{1}[0-9]{0,2}(\,[0-9]{3})*(\.[0-9]{0,2})?|[1-9]{1}\d*(\.[0-9]{0,2})?|0(\.[0-9]{0,2})?|(\.[0-9]{1,2})?)$/.test(v)
			}],
	['validate-captcha', 'Letter combinatie is niet juist .', function(v) {
				// [$]1[##][,###]+[.##]
				// [$]1###+[.##]
				// [$]0.##
				// [$].##
				//document.write(Validation.get('IsEmpty').test(v));
				//alert(document.getElementById("captcha_code").value);
/* 				var myAjax = new Ajax.Request('get_data.php?lorem=ipsum&name=binny',{
				method: 'post',
				onComplete:handlerFunction
			}); */
			re = new RegExp(captcha_code, "g");
			//re = captcha_code;
			return Validation.get('IsEmpty').test(sha1Hash(MD5(v))) || re.test(sha1Hash(MD5(v)));
/* 			if (sha1Hash(MD5(document.getElementById("captcha").value)) == captcha_code)
			{ */
			//ajaxRequest();
/* 			return true;
			}
			else
			return false; */
				//alert('correct');
			//else
				//alert('not correct');
			
			//alert(captcha_code);

/*  var myAjax = new Ajax.Request('/test.php?captcha_code=test',
  {
    method:'get',
    onSuccess: function(transport){
      var response = transport.responseText || "no response text";
      alert("Success! \n\n" + response);
    },
    onFailure: function(){ alert('Something went wrong...') }
  });   */
				

				// if (document.getElementById("captcha_code").value == document.getElementById("captcha").value)
					// alert("thats right");
					 
				//return Validation.get('IsEmpty').test(v) ||  /^\$?\-?([1-9]{1}[0-9]{0,2}(\,[0-9]{3})*(\.[0-9]{0,2})?|[1-9]{1}\d*(\.[0-9]{0,2})?|0(\.[0-9]{0,2})?|(\.[0-9]{1,2})?)$/.test(v)
			}],	
	
	['validate-selection', 'Vul een juist e-mailadres in. Bijvoorbeeld: fred@domain.com .', function (v) {
	//Maak een keuze
				//return Validation.get('IsEmpty').test(v) ;//|| /\w{1,}[@][\w\-]{1,}([.]([\w\-]{1,})){1,3}$/.test(v);
				return true;
			}],		
 	['validate-one-required', 'Selecteer een van de opties.', function (v,elm) {
				var p = elm.parentNode;
				var options = p.getElementsByTagName('INPUT');
				for (i=0; i < options.length;i++)
				{
				if (options[i].checked)
				{
					return true;
					}
				}
				//return $A(options).any(function(elm) {
/* 				
					return $F(elm); */
				//});
			}] 
]);

function trim(value) {
  if(typeof(value) == 'string'){
    value = value.replace(/^\s+/,'');
    value = value.replace(/\s+$/,'');
  }
  return value;
}


function callback(serverData, serverStatus) {       // Called automatically when we get data back from server
  // alert(serverData);     // Display an alert box with the recieved data
  //alert(captcha_code);
}

function ajaxRequest() {
   var AJAX = null;                                 // Initialize the AJAX variable.
   if (window.XMLHttpRequest) {                     // Does this browser have an XMLHttpRequest object?
      AJAX=new XMLHttpRequest();                    // Yes -- initialize it.
   } else {                                         // No, try to initialize it IE style
      AJAX=new ActiveXObject("Microsoft.XMLHTTP");  //  Wheee, ActiveX, how do we format c: again?
   }                                                // End setup Ajax.
   if (AJAX==null) {                                // If we couldn't initialize Ajax...
      alert("Your browser doesn't support AJAX.");  // Sorry msg.                                               
      return false                                  // Return false, couldn't set up ajax
   }
   AJAX.onreadystatechange = function() {                      // When the browser has the request info..
      if (AJAX.readyState==4 || AJAX.readyState=="complete") { //  see if the complete flag is set.
		captcha_code = AJAX.responseText; 
         callback(AJAX.responseText, AJAX.status);             // Pass the response to our processing function
      }                                                        // End Ajax readystate check.
   }
   var url='http://gulbergen.dev.creationpoint.nl/getdata.php?test=testingoutload&doc=sometext.txt'; // This is the URL we will call.
   //var url='http://gulbergen.dev.creationpoint.nl/cms/plugins/captcha/class.captcha.php'; // This is the URL we will call.
   AJAX.open("GET", url, true);                                  // Open the url this object was set-up with.
   AJAX.send(null);  
return   AJAX.responseText; // Send the request.
}


/**
*
*  MD5 (Message-Digest Algorithm)
*  http://www.webtoolkit.info/
*
**/
 
var MD5 = function (string) {
 
	function RotateLeft(lValue, iShiftBits) {
		return (lValue<<iShiftBits) | (lValue>>>(32-iShiftBits));
	}
 
	function AddUnsigned(lX,lY) {
		var lX4,lY4,lX8,lY8,lResult;
		lX8 = (lX & 0x80000000);
		lY8 = (lY & 0x80000000);
		lX4 = (lX & 0x40000000);
		lY4 = (lY & 0x40000000);
		lResult = (lX & 0x3FFFFFFF)+(lY & 0x3FFFFFFF);
		if (lX4 & lY4) {
			return (lResult ^ 0x80000000 ^ lX8 ^ lY8);
		}
		if (lX4 | lY4) {
			if (lResult & 0x40000000) {
				return (lResult ^ 0xC0000000 ^ lX8 ^ lY8);
			} else {
				return (lResult ^ 0x40000000 ^ lX8 ^ lY8);
			}
		} else {
			return (lResult ^ lX8 ^ lY8);
		}
 	}
 
 	function F(x,y,z) { return (x & y) | ((~x) & z); }
 	function G(x,y,z) { return (x & z) | (y & (~z)); }
 	function H(x,y,z) { return (x ^ y ^ z); }
	function I(x,y,z) { return (y ^ (x | (~z))); }
 
	function FF(a,b,c,d,x,s,ac) {
		a = AddUnsigned(a, AddUnsigned(AddUnsigned(F(b, c, d), x), ac));
		return AddUnsigned(RotateLeft(a, s), b);
	};
 
	function GG(a,b,c,d,x,s,ac) {
		a = AddUnsigned(a, AddUnsigned(AddUnsigned(G(b, c, d), x), ac));
		return AddUnsigned(RotateLeft(a, s), b);
	};
 
	function HH(a,b,c,d,x,s,ac) {
		a = AddUnsigned(a, AddUnsigned(AddUnsigned(H(b, c, d), x), ac));
		return AddUnsigned(RotateLeft(a, s), b);
	};
 
	function II(a,b,c,d,x,s,ac) {
		a = AddUnsigned(a, AddUnsigned(AddUnsigned(I(b, c, d), x), ac));
		return AddUnsigned(RotateLeft(a, s), b);
	};
 
	function ConvertToWordArray(string) {
		var lWordCount;
		var lMessageLength = string.length;
		var lNumberOfWords_temp1=lMessageLength + 8;
		var lNumberOfWords_temp2=(lNumberOfWords_temp1-(lNumberOfWords_temp1 % 64))/64;
		var lNumberOfWords = (lNumberOfWords_temp2+1)*16;
		var lWordArray=Array(lNumberOfWords-1);
		var lBytePosition = 0;
		var lByteCount = 0;
		while ( lByteCount < lMessageLength ) {
			lWordCount = (lByteCount-(lByteCount % 4))/4;
			lBytePosition = (lByteCount % 4)*8;
			lWordArray[lWordCount] = (lWordArray[lWordCount] | (string.charCodeAt(lByteCount)<<lBytePosition));
			lByteCount++;
		}
		lWordCount = (lByteCount-(lByteCount % 4))/4;
		lBytePosition = (lByteCount % 4)*8;
		lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80<<lBytePosition);
		lWordArray[lNumberOfWords-2] = lMessageLength<<3;
		lWordArray[lNumberOfWords-1] = lMessageLength>>>29;
		return lWordArray;
	};
 
	function WordToHex(lValue) {
		var WordToHexValue="",WordToHexValue_temp="",lByte,lCount;
		for (lCount = 0;lCount<=3;lCount++) {
			lByte = (lValue>>>(lCount*8)) & 255;
			WordToHexValue_temp = "0" + lByte.toString(16);
			WordToHexValue = WordToHexValue + WordToHexValue_temp.substr(WordToHexValue_temp.length-2,2);
		}
		return WordToHexValue;
	};
 
	function Utf8Encode(string) {
		string = string.replace(/\r\n/g,"\n");
		var utftext = "";
 
		for (var n = 0; n < string.length; n++) {
 
			var c = string.charCodeAt(n);
 
			if (c < 128) {
				utftext += String.fromCharCode(c);
			}
			else if((c > 127) && (c < 2048)) {
				utftext += String.fromCharCode((c >> 6) | 192);
				utftext += String.fromCharCode((c & 63) | 128);
			}
			else {
				utftext += String.fromCharCode((c >> 12) | 224);
				utftext += String.fromCharCode(((c >> 6) & 63) | 128);
				utftext += String.fromCharCode((c & 63) | 128);
			}
 
		}
 
		return utftext;
	};
 
	var x=Array();
	var k,AA,BB,CC,DD,a,b,c,d;
	var S11=7, S12=12, S13=17, S14=22;
	var S21=5, S22=9 , S23=14, S24=20;
	var S31=4, S32=11, S33=16, S34=23;
	var S41=6, S42=10, S43=15, S44=21;
 
	string = Utf8Encode(string);
 
	x = ConvertToWordArray(string);
 
	a = 0x67452301; b = 0xEFCDAB89; c = 0x98BADCFE; d = 0x10325476;
 
	for (k=0;k<x.length;k+=16) {
		AA=a; BB=b; CC=c; DD=d;
		a=FF(a,b,c,d,x[k+0], S11,0xD76AA478);
		d=FF(d,a,b,c,x[k+1], S12,0xE8C7B756);
		c=FF(c,d,a,b,x[k+2], S13,0x242070DB);
		b=FF(b,c,d,a,x[k+3], S14,0xC1BDCEEE);
		a=FF(a,b,c,d,x[k+4], S11,0xF57C0FAF);
		d=FF(d,a,b,c,x[k+5], S12,0x4787C62A);
		c=FF(c,d,a,b,x[k+6], S13,0xA8304613);
		b=FF(b,c,d,a,x[k+7], S14,0xFD469501);
		a=FF(a,b,c,d,x[k+8], S11,0x698098D8);
		d=FF(d,a,b,c,x[k+9], S12,0x8B44F7AF);
		c=FF(c,d,a,b,x[k+10],S13,0xFFFF5BB1);
		b=FF(b,c,d,a,x[k+11],S14,0x895CD7BE);
		a=FF(a,b,c,d,x[k+12],S11,0x6B901122);
		d=FF(d,a,b,c,x[k+13],S12,0xFD987193);
		c=FF(c,d,a,b,x[k+14],S13,0xA679438E);
		b=FF(b,c,d,a,x[k+15],S14,0x49B40821);
		a=GG(a,b,c,d,x[k+1], S21,0xF61E2562);
		d=GG(d,a,b,c,x[k+6], S22,0xC040B340);
		c=GG(c,d,a,b,x[k+11],S23,0x265E5A51);
		b=GG(b,c,d,a,x[k+0], S24,0xE9B6C7AA);
		a=GG(a,b,c,d,x[k+5], S21,0xD62F105D);
		d=GG(d,a,b,c,x[k+10],S22,0x2441453);
		c=GG(c,d,a,b,x[k+15],S23,0xD8A1E681);
		b=GG(b,c,d,a,x[k+4], S24,0xE7D3FBC8);
		a=GG(a,b,c,d,x[k+9], S21,0x21E1CDE6);
		d=GG(d,a,b,c,x[k+14],S22,0xC33707D6);
		c=GG(c,d,a,b,x[k+3], S23,0xF4D50D87);
		b=GG(b,c,d,a,x[k+8], S24,0x455A14ED);
		a=GG(a,b,c,d,x[k+13],S21,0xA9E3E905);
		d=GG(d,a,b,c,x[k+2], S22,0xFCEFA3F8);
		c=GG(c,d,a,b,x[k+7], S23,0x676F02D9);
		b=GG(b,c,d,a,x[k+12],S24,0x8D2A4C8A);
		a=HH(a,b,c,d,x[k+5], S31,0xFFFA3942);
		d=HH(d,a,b,c,x[k+8], S32,0x8771F681);
		c=HH(c,d,a,b,x[k+11],S33,0x6D9D6122);
		b=HH(b,c,d,a,x[k+14],S34,0xFDE5380C);
		a=HH(a,b,c,d,x[k+1], S31,0xA4BEEA44);
		d=HH(d,a,b,c,x[k+4], S32,0x4BDECFA9);
		c=HH(c,d,a,b,x[k+7], S33,0xF6BB4B60);
		b=HH(b,c,d,a,x[k+10],S34,0xBEBFBC70);
		a=HH(a,b,c,d,x[k+13],S31,0x289B7EC6);
		d=HH(d,a,b,c,x[k+0], S32,0xEAA127FA);
		c=HH(c,d,a,b,x[k+3], S33,0xD4EF3085);
		b=HH(b,c,d,a,x[k+6], S34,0x4881D05);
		a=HH(a,b,c,d,x[k+9], S31,0xD9D4D039);
		d=HH(d,a,b,c,x[k+12],S32,0xE6DB99E5);
		c=HH(c,d,a,b,x[k+15],S33,0x1FA27CF8);
		b=HH(b,c,d,a,x[k+2], S34,0xC4AC5665);
		a=II(a,b,c,d,x[k+0], S41,0xF4292244);
		d=II(d,a,b,c,x[k+7], S42,0x432AFF97);
		c=II(c,d,a,b,x[k+14],S43,0xAB9423A7);
		b=II(b,c,d,a,x[k+5], S44,0xFC93A039);
		a=II(a,b,c,d,x[k+12],S41,0x655B59C3);
		d=II(d,a,b,c,x[k+3], S42,0x8F0CCC92);
		c=II(c,d,a,b,x[k+10],S43,0xFFEFF47D);
		b=II(b,c,d,a,x[k+1], S44,0x85845DD1);
		a=II(a,b,c,d,x[k+8], S41,0x6FA87E4F);
		d=II(d,a,b,c,x[k+15],S42,0xFE2CE6E0);
		c=II(c,d,a,b,x[k+6], S43,0xA3014314);
		b=II(b,c,d,a,x[k+13],S44,0x4E0811A1);
		a=II(a,b,c,d,x[k+4], S41,0xF7537E82);
		d=II(d,a,b,c,x[k+11],S42,0xBD3AF235);
		c=II(c,d,a,b,x[k+2], S43,0x2AD7D2BB);
		b=II(b,c,d,a,x[k+9], S44,0xEB86D391);
		a=AddUnsigned(a,AA);
		b=AddUnsigned(b,BB);
		c=AddUnsigned(c,CC);
		d=AddUnsigned(d,DD);
	}
 
	var temp = WordToHex(a)+WordToHex(b)+WordToHex(c)+WordToHex(d);
 
	return temp.toLowerCase();
}

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */
/*  SHA-1 implementation in JavaScript (c) Chris Veness 2002-2009                                 */
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */

function sha1Hash(msg)
{
    // constants [§4.2.1]
    var K = [0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6];


    // PREPROCESSING 
 
    msg += String.fromCharCode(0x80); // add trailing '1' bit (+ 0's padding) to string [§5.1.1]

    // convert string msg into 512-bit/16-integer blocks arrays of ints [§5.2.1]
    var l = msg.length/4 + 2;  // length (in 32-bit integers) of msg + ‘1’ + appended length
    var N = Math.ceil(l/16);   // number of 16-integer-blocks required to hold 'l' ints
    var M = new Array(N);
    for (var i=0; i<N; i++) {
        M[i] = new Array(16);
        for (var j=0; j<16; j++) {  // encode 4 chars per integer, big-endian encoding
            M[i][j] = (msg.charCodeAt(i*64+j*4)<<24) | (msg.charCodeAt(i*64+j*4+1)<<16) | 
                      (msg.charCodeAt(i*64+j*4+2)<<8) | (msg.charCodeAt(i*64+j*4+3));
        }
    }
    // add length (in bits) into final pair of 32-bit integers (big-endian) [5.1.1]
    // note: most significant word would be (len-1)*8 >>> 32, but since JS converts
    // bitwise-op args to 32 bits, we need to simulate this by arithmetic operators
    M[N-1][14] = ((msg.length-1)*8) / Math.pow(2, 32); M[N-1][14] = Math.floor(M[N-1][14])
    M[N-1][15] = ((msg.length-1)*8) & 0xffffffff;

    // set initial hash value [§5.3.1]
    var H0 = 0x67452301;
    var H1 = 0xefcdab89;
    var H2 = 0x98badcfe;
    var H3 = 0x10325476;
    var H4 = 0xc3d2e1f0;

    // HASH COMPUTATION [§6.1.2]

    var W = new Array(80); var a, b, c, d, e;
    for (var i=0; i<N; i++) {

        // 1 - prepare message schedule 'W'
        for (var t=0;  t<16; t++) W[t] = M[i][t];
        for (var t=16; t<80; t++) W[t] = ROTL(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16], 1);

        // 2 - initialise five working variables a, b, c, d, e with previous hash value
        a = H0; b = H1; c = H2; d = H3; e = H4;

        // 3 - main loop
        for (var t=0; t<80; t++) {
            var s = Math.floor(t/20); // seq for blocks of 'f' functions and 'K' constants
            var T = (ROTL(a,5) + f(s,b,c,d) + e + K[s] + W[t]) & 0xffffffff;
            e = d;
            d = c;
            c = ROTL(b, 30);
            b = a;
            a = T;
        }

        // 4 - compute the new intermediate hash value
        H0 = (H0+a) & 0xffffffff;  // note 'addition modulo 2^32'
        H1 = (H1+b) & 0xffffffff; 
        H2 = (H2+c) & 0xffffffff; 
        H3 = (H3+d) & 0xffffffff; 
        H4 = (H4+e) & 0xffffffff;
    }

    return H0.toHexStr() + H1.toHexStr() + H2.toHexStr() + H3.toHexStr() + H4.toHexStr();
}

//
// function 'f' [§4.1.1]
//
function f(s, x, y, z) 
{
    switch (s) {
    case 0: return (x & y) ^ (~x & z);           // Ch()
    case 1: return x ^ y ^ z;                    // Parity()
    case 2: return (x & y) ^ (x & z) ^ (y & z);  // Maj()
    case 3: return x ^ y ^ z;                    // Parity()
    }
}

//
// rotate left (circular left shift) value x by n positions [§3.2.5]
//
function ROTL(x, n)
{
    return (x<<n) | (x>>>(32-n));
}

//
// extend Number class with a tailored hex-string method 
//   (note toString(16) is implementation-dependant, and 
//   in IE returns signed numbers when used on full words)
//
Number.prototype.toHexStr = function()
{
    var s="", v;
    for (var i=7; i>=0; i--) { v = (this>>>(i*4)) & 0xf; s += v.toString(16); }
    return s;
}
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */