if (document.images) {

	 image1on = new Image();
	 image1on.src = "images/nav_about_on.gif";
	 image2on = new Image();
	 image2on.src = "images/nav_salesservice_on.gif";
	 image3on = new Image();
	 image3on.src = "images/nav_alpacas_on.gif";
	 image4on = new Image();
	 image4on.src = "images/nav_investing_on.gif";
	 image5on = new Image();
	 image5on.src = "images/nav_contact_on.gif";
	 
	 image1off = new Image(); 
	 image1off.src = "images/nav_about_off.gif"; 
	 image2off = new Image(); 
	 image2off.src = "images/nav_salesservice_off.gif";
	 image3off = new Image();
	 image3off.src = "images/nav_alpacas_off.gif";
	 image4off = new Image();
	 image4off.src = "images/nav_investing_off.gif";
	 image5off = new Image();
	 image5off.src = "images/nav_contact_off.gif";

} 

function imgOn(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "on.src");
}
}

function imgOff(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "off.src");
}
}