function link_hover(id){
	var ct;
	for(ct=1 ; ct <= 6 ; ct++){
		if(document.getElementById("sub" + ct)){
			var obj = document.getElementById("sub" + ct);
			if(ct == id){
				obj.style.display="block";
			}
			else{
				obj.style.display="none";
			}
		}
	}
}