// Rollover  v1.0

// http://www.dithered.com/javascript/rollover/index.html

// code by Chris Nott (chris@NOSPAMdithered.com - remove NOSPAM)



var rolloverImageOff = new Array();

var rolloverImageOn = new Array();

var rolloverCurrent = '';





// Preload rollover images

function rolloverInit() {

	if (document.images) {

		

		// for each rollover, preload both states and put filename in an associative array

		for (var i = 0; i < rolloverImageOnFiles.length; i++) {

			rolloverCurrentName = rolloverImageTagNames[i];



			rolloverImageOff[rolloverCurrentName] = new Image();

			rolloverImageOn[rolloverCurrentName] = new Image();

			rolloverImageOff[rolloverCurrentName].src = rolloverImageDirectory + rolloverImageOffFiles[i];

			rolloverImageOn[rolloverCurrentName].src = rolloverImageDirectory + rolloverImageOnFiles[i];

		}

	}

}





// Preload rollover images

function rolloverSingleInit() {

	if (document.images) {

		

		// for each rollover, preload both states and put filename in an associative array

		for (var i = 0; i < rolloverImageTagNames.length; i++) {

			rolloverCurrentName = rolloverImageTagNames[i];



			rolloverImageOff[rolloverCurrentName] = new Image();

			rolloverImageOn[rolloverCurrentName] = new Image();

			rolloverImageOff[rolloverCurrentName].src = rolloverImageDirectory + rolloverImageOffFile;

			rolloverImageOn[rolloverCurrentName].src = rolloverImageDirectory + rolloverImageOnFile;

		}

	}

}





// On state activation

function rolloverOn(img, layer) {

	if (document.images && rolloverImageOn[img]) {

		

		// rollovers in layers in NS4 require a different image reference

		if (layer != null && document.layers) {

			if (typeof(layer) == 'object') layer.document.images[img].src = rolloverImageOn[img].src;

			else if (typeof(layer) == 'string') eval('document.layers["' + layer + '"].document.images[img].src = rolloverImageOn[img].src');

		}

		

		// non-layer rollovers in NS4 and all rollovers in other browsers

		else if (document.images[img]) document.images[img].src = rolloverImageOn[img].src;

	}

}





// Off state activation

function rolloverOff(img, layer) {

	if (document.images && rolloverImageOff[img]) {



		// rollovers in layers in NS4 require a different image reference

		if (layer != null && document.layers) {

			if (typeof(layer) == 'object') layer.document.images[img].src = rolloverImageOff[img].src;

			else if (typeof(layer) == 'string') eval('document.layers["' + layer + '"].document.images[img].src = rolloverImageOff[img].src');

		}

		

		// non-layer rollovers in NS4 and all rollovers in other browsers

		else if (document.images[img]) document.images[img].src = rolloverImageOff[img].src;

	}

}





// Rollover with state function (not used in standard rollovers; included for flexability)

function rolloverSetCurrent(img) {

	if (rolloverCurrent) rolloverOff(rolloverCurrent);

	rolloverCurrent = img;

	rolloverOn(rolloverCurrent);

}











//Mask the DOM

if(document.layers){

pre = 'document.';

post = '';

}

if(document.getElementById){

pre = 'document.getElementById("';

post = '").style';

}

if(document.all){

pre = 'document.all.';

post = '.style';

}







//Visibility code

var currentLayer = 'initialLyr';

function showLayer(lyr){

	hideLayer(currentLayer);

	eval(pre + lyr + post).visibility = 'visible';

	currentLayer = lyr;

}



function hideLayer(lyr){

	eval(pre + lyr + post).visibility = 'hidden';

}







//Launch exhibits pop-up

var w = screen.availWidth;

var h = screen.availHeight;



var popW = 478, popH = 448;



var leftPos = (w-popW)/2, topPos = (h-popH)/2;

       

     function launchWindow(launchURL, name) {

     window.open(launchURL,name,'width=' + popW + ',height=' + popH + ',top=' + topPos + ',left=' + leftPos + ',screenX=5,screeny=5,directories=no,location=no,menubar=no,scrollbars=no,status=no,toolbar=no,resizable=no');

     }