function top_nav_mouse_over(objImg) {
	var strImgURL = objImg.src;
	objImg.src = strImgURL.replace(/.gif/,"_over.gif");
}

function top_nav_mouse_out(objImg) {
	var strImgURL = objImg.src;
	objImg.src = strImgURL.replace(/_over.gif/,".gif");
}