Javascript Number decorateFloat(decimals, decSeparator)

Number.prototype.decorateFloat = function (decimals, decSeparator) {
 if(decSeparator == undefined)
  decSeparator = '.';
 var price = this;
 var decPattern = '';
 
 for(var i = 0; i < decimals; i++)
  decPattern += '0';
  
 price = price.roundFloat(decimals);/*  w  w w . j a  va2  s. c om*/
 var split = price.toString().split('.');
 if(split[1] == undefined)
  split[1] = '';
 var decor = decPattern.substring(split[1].length, decimals);
 split[1] = split[1]+decor;
 
 return split.join(decSeparator);
};