Javascript UUID

 function UUID(){
     this.id = this.createUUID();
 }
 UUID.prototype.valueOf = function(){ return this.id; };
 UUID.prototype.toString = function(){ return this.id; };
 UUID.prototype.createUUID = function(){
     var dg = new Date(1582, 10, 15, 0, 0, 0, 0);
     var dc = new Date();
     var t = dc.getTime() - dg.getTime();
     var tl = UUID.getIntegerBits(t,0,31);
     var tm = UUID.getIntegerBits(t,32,47);
     var thv = UUID.getIntegerBits(t,48,59) + '1'; // version 1, security version is 2
     var csar = UUID.getIntegerBits(UUID.rand(4095),0,7);
     var csl = UUID.getIntegerBits(UUID.rand(4095),0,7);
     var n = UUID.getIntegerBits(UUID.rand(8191),0,7) +
             UUID.getIntegerBits(UUID.rand(8191),8,15) +
             UUID.getIntegerBits(UUID.rand(8191),0,7) +
             UUID.getIntegerBits(UUID.rand(8191),8,15) +
             UUID.getIntegerBits(UUID.rand(8191),0,15); // this last number is two octets long
     return tl + tm  + thv  + csar + csl + n;
 };
 UUID.getIntegerBits = function(val,start,end){
     var base16 = UUID.returnBase(val,16);
     var quadArray = [];
     var quadString = '';
     for(i=0;i< base16.length;i++){
         quadArray.push(base16.substring(i,i+1));  
     }
     for(i=Math.floor(start/4);i<=Math.floor(end/4);i++){
         if(!quadArray[i] || quadArray[i] == '') quadString += '0';
         else quadString += quadArray[i];
     }
     return quadString;
 };
 UUID.returnBase = function(number, base){
     return (number).toString(base).toUpperCase();
 };
 UUID.rand = function(max){
     return Math.floor(Math.random() * (max + 1));
 };