Javascript Number formatMoney(c,t)

Number.prototype.formatMoney = function(c,t){
 var n = this, //from  ww w. java 2  s .co m
  c = isNaN(c = Math.abs(c)) ? 2 : c, 
  t = t == undefined ? "," : t, 
  s = n < 0 ? "-" : "", 
  i = parseInt(n = Math.abs(+n || 0).toFixed(c)) + "", 
  j = (j = i.length) > 3 ? j % 3 : 0;
   return s + (j ? i.substr(0, j) + t : "") + i.substr(j).replace(/(\d{3})(?=\d)/g, "$1" + t);
 };