sfHover = function() {
	var sfEls = document.getElementById("op_de_hoogte");
	sfEls.onmouseover=function() {
		this.className+=" hover";
	}
	sfEls.onmouseout=function() {
		this.className=this.className.replace(new RegExp(" hover\\b"), "");
	}	
}
if (window.attachEvent) window.attachEvent("onload", sfHover);