function hide( layer ) {
	var obj = document.getElementById( layer );
	if( obj ) {
		obj.className = "hidden";
	}
}

function show( layer ) {
	var obj = document.getElementById( layer );
	if( obj ) {
		obj.className = "";
	}
}

function applyClass( obj, className ) {
	obj.className = className;
}

function removeClass( obj, className ) {
	obj.className = obj.className.replace( className,"");
}