tt = null;
document.onmousemove = updateToolTip;

function updateToolTip(e) {
	if (tt != null) {
		x = (document.all) ? event.clientX : e.pageX;
		y = (document.all) ? event.clientY : e.pageY;
		tt.style.left = (x + 20) + "px";
	    tt.style.top   = (y + 20) + "px";
	}
}
function showToolTip(id) {
  tt = document.getElementById(id);
  tt.style.display = "block"
}

function hideToolTip() {
  tt.style.display = "none";
}