checkh4 = function() {
	if (document.getElementById("contenu")) {
		var toCheck = document.getElementById("contenu").getElementsByTagName("H4");
		for (var i=0; i<toCheck.length; i++) {
			toCheck[i].innerHTML = '<span>' + toCheck[i].innerHTML + '</span>';
		}
	}
}

function addEvent(obj, evType, fn){
 if (obj.addEventListener){
   obj.addEventListener(evType, fn, true);
   return true;
 } else if (obj.attachEvent){
   var r = obj.attachEvent("on"+evType, fn);
   return r;
 } else {
   return false;
 }
}

addEvent(window, 'load', checkh4);