// JavaScript Document
function hatTrick(hatNumber) {
      var total = 3;	// total de background
      var bodyTag = document.getElementsByTagName('body')[0];
      var classList = bodyTag.className;
      if (classList.indexOf("hat") > -1) {
            var tempClasses = new Array();
            var classes = classList.split(" ");
            var j = 0;
            for(i = 0; i < classes.length; i++) {
                  if(classes[i].substr(0,3) != "hat") tempClasses[j++] = classes[i];
            }
            classList = tempClasses.join(" ");
      }
      if (!hatNumber) 
	  	hatNumber = Math.floor(total*Math.random());
      var newHat = " hat" + hatNumber;
      bodyTag.className = classList + newHat + "";
}
if(typeof hatTrick == "function") hatTrick();