//determine browser
var w3c = document.getElementById ? true : false;

//preload rollover images
//home
img1 = new Image();
img1.src = "http://www.neuroengineering.upenn.edu/boahen/img/navHome_over.gif";
//labs
img2 = new Image();
img2.src = "http://www.neuroengineering.upenn.edu/boahen/img/navLabs_over.gif";
//projects
img3 = new Image();
img3.src = "http://www.neuroengineering.upenn.edu/boahen/img/navProj_over.gif";
//methods
img4 = new Image();
img4.src = "http://www.neuroengineering.upenn.edu/boahen/img/navMethods_over.gif";
//people
img5 = new Image();
img5.src = "http://www.neuroengineering.upenn.edu/boahen/img/navPeo_over.gif";
//publication
img6 = new Image();
img6.src = "http://www.neuroengineering.upenn.edu/boahen/img/navPub_over.gif";

//Rollovers
stuck = new Image;
function MM_swapImage() 
{
	var i,j=0,objStr,obj,swapArray=new Array,oldArray=document.MM_swapImgData;
	for (i=0; i < (MM_swapImage.arguments.length-2); i+=3) 
	{
		objStr = MM_swapImage.arguments[(navigator.appName=='Netscape')?i:i+1];
		if ((objStr.indexOf('document.layers[')==0 && document.layers==null) ||
		(objStr.indexOf('document.all[')==0 && document.all==null))
		{
			objStr = 'document'+objStr.substring(objStr.lastIndexOf('.'),objStr.length);
		}
		obj = eval(objStr);
		if (obj != null && obj != stuck) 
		{
			swapArray[j++] = obj;
			swapArray[j++] = (oldArray==null || oldArray[j-1]!=obj)?obj.src:oldArray[j];
			obj.src = MM_swapImage.arguments[i+2];
		} 
	}
	document.MM_swapImgData = swapArray;
}