function imgOn(imgName)
{
	if(document.images)
	{
		document[imgName].src = eval(imgName + "On.src");
	}
}

function imgOff(imgName)
{
	if(document.images)
	{
		document[imgName].src = eval(imgName + "Off.src");
	}
}


function showLayer(layerName)
{
	if(document.all) // IE
	{
		document.all[layerName].style.visibility = 'visible';
	}
	else if(document.layers) // NS
	{
 		document.layers[layerName].visibility = 'visible';
	}
	else // DOM
	{
		document.getElementById(layerName).style.visibility = 'visible';
	}
}

function hideLayer(layerName)
{
	if(document.all) // IE
	{
		document.all[layerName].style.visibility = 'hidden';
	}
	else if(document.layers) // NS
	{
		document.layers[layerName].visibility = 'hidden';
	}
	else // DOM
	{
		document.getElementById(layerName).style.visibility = 'hidden';
	}
}


patientsOn = new Image(); patientsOn.src = "images/nav/index_patients_on.gif";
patientsOff = new Image(); patientsOff.src = "images/nav/index_patients_off.gif";
residentsOn = new Image(); residentsOn.src = "images/nav/index_residents_on.gif";
residentsOff = new Image(); residentsOff.src = "images/nav/index_residents_off.gif";
facultyOn = new Image(); facultyOn.src = "images/nav/index_faculty_on.gif";
facultyOff = new Image(); facultyOff.src = "images/nav/index_faculty_off.gif";
researchOn = new Image(); researchOn.src = "images/nav/index_research_on.gif";
researchOff = new Image(); researchOff.src = "images/nav/index_research_off.gif";
newsOn = new Image(); newsOn.src = "images/nav/index_news_on.gif";
newsOff = new Image(); newsOff.src = "images/nav/index_news_off.gif";
alumniOn = new Image(); alumniOn.src = "images/nav/index_alumni_on.gif";
alumniOff = new Image(); alumniOff.src = "images/nav/index_alumni_off.gif";

var blnReset = false;

function showtopnav(menuname)
{
	resettopnav();
	showLayer(menuname+'Menu');
	showLayer('topNavReset');
	blnReset = false;
}
function resettopnav()
{
	hideLayer('patientsMenu');
	hideLayer('residentsMenu');
	hideLayer('facultyMenu');
	hideLayer('researchMenu');
	hideLayer('newsMenu');
	hideLayer('alumniMenu');
	hideLayer('topNavReset');
	blnReset = false;
}

/*
//Drop each of the subnavs down 2px if N6:
if(navigator.appName == "Netscape" && !document.layers)
{
        n6subnavDrop('patientsMenu');
        n6subnavDrop('residentsMenu');
        n6subnavDrop('facultyMenu');
        n6subnavDrop('researchMenu');
        n6subnavDrop('newsMenu');
        n6subnavDrop('alumniMenu');
}
function n6subnavDrop(layername)
{
        document.getElementById(layername).style.top = "35px";
}*/