currency format.js

// options object example
/*
{
  decimals:2,
  decimalSign:",",
  thousandSep: " ",
  currency:"SEK"
}
*/

Number.prototype.toCurrency = function(options){
  var o = options, d = Math.pow(10,o.decimals), n = Math.round(d*this)/d, n2 = '';
  var dec = (n +'').split('.')[1] || '0';
  while(dec.length < o.decimals){dec += '0';}
  ((o.decimals ? Math.floor(n) : Math.round(n)) + '').split('').reverse().forEach(
    function(x,i){
      n2 = (i%3 ==2 ? ' ' : '') + x + n2;
    }
  );
  return n2 + (o.decimals ? options.decimalSign + dec : '') +
    (options.currency ? ' ' + options.currency : '');
};