function convertToRoman(num) {

  var str = num.toString().split("").reverse(),
      result = [];

  var rnums = {

    1: ["","I","II","III","IV","V","VI","VII","VIII", "IX"],
    2: ["","X", "XX", "XXX", "XL","L", "LX","LXX","LXXX","XC"],
    3: ["","C", "CC", "CCC", "CD","D", "DC", "DCC","DCCC","CM"],
    4: ["","M", "MM", "MMM"]
  };

  for (var i = str.length - 1 ; i >= 0; i-=1) {

      var val = parseInt(str[i]);
      result.push(rnums[i + 1][val]);

  }

  result = result.join("");

  return result;
}

convertToRoman(36);