Decimal To Fraction

Change from decimal to fraction using javascript:

I got a sample after searching on google and found a good sample, i can't remember the website link, but i tried it in a website and it worked fine with me.

Number.prototype.fraction=fraction;
      function fraction(item){
          if(item.value != "" && item.value.indexOf(".")!=-1 && item.value.indexOf("/")==-1)
          {
              decimal=item.value
              if(!decimal){
                  decimal=this;
              }
              whole = String(decimal).split('.')[0];
              decimal = parseFloat("."+String(decimal).split('.')[1]);
              num = "1";
              for(z=0; z<String(decimal).length-2; z++){
              num += "0";
              }
              decimal = parseInt(decimal*num);
              num = parseInt(num);
              for(z=2; z<decimal+1; z++){
                  if(decimal%z==0 && num%z==0){
                      decimal = decimal/z;
                      num = num/z;
                      z=2;
                  }
              }
              item.value= ((whole==0)?"" : whole+" ")+decimal+"/"+num;
          }
      }