//Add a class name to an objects class list
function addClassName(obj,classname) {
	var classes = document.getElementById(obj).className;
	if(classes.indexOf(classname)>=0) return;
	classes += " " + classname;
	document.getElementById(obj).className = classes;
}


//remove a class name from an objects class list
function removeClassName(obj,classname)
{
	var classes = document.getElementById(obj).className;
	if(classes.indexOf(classname)<0) return;
	var cl = classes.split(" ");
	classes = '';
	for (i=0; i<cl.length; i++)
	{
		if(cl[i]!=classname) classes += cl[i] + " ";
	}
	document.getElementById(obj).className = classes;
}