//========================= pre-cache images =========================//
if (document.images) {
	var imgArray 	= new Array();
	var temp 		= new Array();
}



function preload(imgName, dir, ext) {
	imgArray[imgName + '_off']		= new Image();
	imgArray[imgName + '_off'].src	= dir + imgName + '_off.' + ext;
	imgArray[imgName + '_on']		= new Image();
	imgArray[imgName + '_on'].src	= dir + imgName + '_on.' + ext;
}



//========================= standard rollover =========================//
function rollover(imgName, active) {
	if (document.images && document.images[imgName]) {
		if (imgName == selected) return;
		if (imgName == header) return;
		active? document[imgName].src = imgArray[imgName + '_on'].src : document[imgName].src = imgArray[imgName + '_off'].src;
	}
}