var theSelectedTip;
theSelectedTip = "";

function showTip(theTip) {
	if (theSelectedTip) {
		document.getElementById(theSelectedTip).style.display = 'none';
	}
	document.getElementById(theTip).style.display = 'block';
	theSelectedTip = theTip;
}

function hideTip(theTip) {
	document.getElementById(theTip).style.display = 'none';
	theSelectedTip = "";
}