// atach event
	
function addEvent(obj, evType, fn){ 
	 if (obj.addEventListener){ 
   		obj.addEventListener(evType, fn, false); 
	   	return true; 
	 } else if (obj.attachEvent){ 
	   var r = obj.attachEvent("on"+evType, fn); 
	   return r; 
	 } else { 
	   return false; 
	 } 
}