/*
* Get the class string from the object
* @param object o the DOM object 
* @return string the class string of the object
*/
//var getClass=function(o){
var getClassName=function(o){
	return o.className;
}
/*
* Set the class string from the object
* @param string cls the class string to be set
* @param object o the DOM object where
* the class string to be set to
*/
//var setClass=function(o){
var setClassName=function(cls,o){
	o.className=cls;
}
/*
* Parse the classes list to array by split(" ")
* @param string cl a string of class or a list of classes
* @return array with the element of class name
*/
var getClassArray=function(cl){
	if(cl && typeof(cl)=="string")
	return cl.split(" ");
	else return cl;
}
/*
* If the class is listed in the classes list ,return true
* @param string cl a single class name 
* @param string cls class name list
* @return true if the class is listed 
* in the classes list.else return false.
*/
var matchClass=function(cl,cls){
	if(!cls) return false;
	cls= getClassArray(cls);
	for(var c in cls) if(cl==cls[c]) return true;
	return cl==cls;
}
/*
* remove one of the classes from the object
* @param string cl a single class name 
* @param string cls class name list
*/
var removeClass=function(cl,o){
	var cls=getClassArray(getClassName(o));
	var _cls="";
	for(var i in cls) if (cl!=cls[i]) _cls+=" "+cls[i];
	setClassName(_cls,o);
}
/*
* add a class to the object
* @param string cl a single class name 
* @param object o the DOM object
* where the class string to be ADD to
*/
var addClass=function(cl,o){
	removeClass(cl,o);
	setClassName(getClassName(o)+" "+cl,o);
}