//Common Javascript functions for dom and event functions
var Dom={
	get:function(l){
		return (typeof l==='string')?document.getElementById(l):l;
	},
	getFirstTag:function(l,tag){
		var el=(!l)?document:Dom.get(l);
		return el.getElementsByTagName(tag)[0];
	},
	forEachElement:function(id,tag,fn){
		var el=Dom.get(id);
		if(el){
			var tags=Dom.get(id).getElementsByTagName(tag);
			for(var i=0;i<tags.length;i++){
				fn.call(tags[i])
			}
		}
	},
	addClassName:function(l,classToAdd){
		var el=Dom.get(l);
		var classes=' '+el.className+' ';		
		if(classes.indexOf(' '+classToAdd+' ')===-1){
			el.className+=((!el.className)?'':' ')+classToAdd;
		}
	},
	removeClassName:function(l,classToRemove){
		var el=Dom.get(l);
		var classes=' '+el.className+' ';		
		classes=classes.replace(' '+classToRemove,'');
		el.className=classes.slice(1,classes.length-1);
	}	
}
var Event = {
	  add: function() {
		if (window.addEventListener) {
		  return function(el, type, fn) {
			Dom.get(el).addEventListener(type, fn, false);
		  };
		} else if (window.attachEvent) {
		  return function(el, type, fn) {
			var f = function() {
			  fn.call(Dom.get(el), window.event);
			};
			Dom.get(el).attachEvent('on' + type, f);
		  };
		}
	  }()
};