if (document.images) {

   img01off = new Image();
   img01off.src = "images/nv_home00.gif";
   img02off = new Image();
   img02off.src = "images/nv_news00.gif";
   img03off = new Image();
   img03off.src = "images/nv_driver00.gif";
   img05off = new Image();
   img05off.src = "images/nv_calendar00.gif";
   img06off = new Image();
   img06off.src = "images/nv_gallery00.gif";
   img07off = new Image();
   img07off.src = "images/nv_photos00.gif";
   img08off = new Image();
   img08off.src = "images/nv_links00.gif";
   img09off = new Image();
   img09off.src = "images/nv_contact00.gif";

   img01on = new Image();
   img01on.src = "images/nv_home01.gif";
   img02on = new Image();
   img02on.src = "images/nv_news01.gif";
   img03on = new Image();
   img03on.src = "images/nv_driver01.gif";
   img05on = new Image();
   img05on.src = "images/nv_calendar01.gif";
   img06on = new Image();
   img06on.src = "images/nv_gallery01.gif";
   img07on = new Image();
   img07on.src = "images/nv_photos01.gif";
   img08on = new Image();
   img08on.src = "images/nv_links01.gif";
   img09on = new Image();
   img09on.src = "images/nv_contact01.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");
	}
}