var mouse_x;
var mouse_y;

function trackMouse(evt) {
	mouse_x = (document.all) ? event.clientX + (document.documentElement.scrollLeft ? document.documentElement.scrollLeft : document.body.scrollLeft) : evt.pageX;
	mouse_y = (document.all) ? event.clientY + (document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop) : evt.pageY;	
}

function showTooltip(tip) {
	var obj = document.getElementById('tooltip');
	obj.innerHTML = tip;
	obj.style.top = (mouse_y + 10) + 'px';
	obj.style.left = (mouse_x) + 'px';	
	obj.style.visibility = 'visible';
}

function hideTooltip() {
	var obj = document.getElementById('tooltip').style;
	obj.visibility = 'hidden';
}

document.onmouseover = trackMouse;