function popupimage(myId, mySrc, descId, descText){	
		// myId = the ID of the image to be swapped
		// mySrc = path to the image to be swapped in
		// descId = ID of span that will have text swapped in
		// descText = text to swap in
		
		document.getElementById(myId).src = mySrc;
		document.getElementById(descId).innerHTML = descText;
		
}

function navrollover(myId, mySrc){
		document.getElementById(myId).src = mySrc;
		
}