function getRef(obj) {
	obj = document.getElementById(obj);
	return obj;
}


function swapImg(buttonid, buttsrc) {
	getRef(buttonid).src=buttsrc;
}

function rollOver(ref) {
	imref= '../x_images/nav/' + ref + '_over.gif'
	swapImg(ref, imref);
}
function rollOut(ref) {
	imref= '../x_images/nav/' + ref + '.gif'
	swapImg(ref, imref);
}