function hasClass(obj,cname)
{
	var regex = new RegExp('\\b'+cname+'\\b');
	return regex.test(obj.className);
}

function addClass(obj,cname)
{
	if (!hasClass(obj,cname))
		obj.className = obj.className+' '+cname;
}

function addClasses(obj,classes)
{
	for (var i=0; i < classes.length; i++)
		addClass(obj,classes[i]);
}

function remClass(obj,cname)
{
	if (hasClass(obj,cname))
	{
		//obj.className = obj.className.replace(cname,'');

		var regex = new RegExp('\\s*\\b'+cname+'\\b','g');
		obj.className = obj.className.replace(regex,'');
	}
}

function remClasses(obj,classes)
{
	for (var i=0; i < classes.length; i++)
		remClass(obj,classes[i]);
}