var timerID = setTimeout("changeExpert()",5000);
function changeExpert(){
	clearTimeout (timerID);

	var obj1 = document.getElementById("exp1");
	var obj2 = document.getElementById("exp2");

	if ( obj1 != null && obj2 != null ){
		if ( obj1.style.display == "block" ){
			obj1.style.display = "none";
			obj2.style.display = "block";
		}
		else{
			obj1.style.display = "block";
			obj2.style.display = "none";
		}
	}
	timerID = setTimeout("changeExpert()",5000);
}