function createHexArray(n) {
 this.length = n;
 for (var i = 1; i <= n; i++) this[i] = i - 1;
 this[11] = "A";
 this[12] = "B";
 this[13] = "C";
 this[14] = "D";
 this[15] = "E";
 this[16] = "F";
 return this;
}

hx = new createHexArray(16);

function convertToHex(x) {
 if (x < 17) x = 16;
 var high = x / 16;
 var s = high+"";
 s = s.substring(0, 2);
 high = parseInt(s, 10);
 var left = hx[high + 1];
 var low = x - high * 16;
 if (low < 1) low = 1;
 s = low + "";
 s = s.substring(0, 2);
 low = parseInt(s, 10);
 var right = hx[low + 1];
 var string = left + "" + right;
 return string;
}
                                                                                                                                                   
function makeRainbow(text) {
 text = text.substring(0, text.length);
 color_d1 = 255;
 mul = color_d1 / text.length;
 for(var i = 0; i < text.length; i++) {
  color_d1 = 255*Math.sin(i / (text.length / 3));
  color_h1 = convertToHex(color_d1);
  color_d2 = mul * i;
  color_h2 = convertToHex(color_d2);
  k = text.length;
  j = k - i;
  if (j < 0) j = 0;
  color_d3 = mul * j;
  color_h3 = convertToHex(color_d3);
  document.write("<FONT COLOR=\"#" + color_h1 + color_h2 + color_h3 + "\">" + text.substring(i, i + 1) + "</FONT>");
 }
}