if (document.images) {
	
	// ON images
	img1on = new Image();
	img1on.src = "graphics/navagation_02_over.gif";
	img2on = new Image();
	img2on.src = "graphics/navagation_04_over.gif";
	img3on = new Image();
	img3on.src = "graphics/navagation_06_over.gif";
	img4on = new Image();
	img4on.src = "graphics/navagation_08_over.gif";


	
	// OFF images
	img1off = new Image();
	img1off.src = "graphics/navagation_02.gif";
	img2off = new Image();
	img2off.src = "graphics/navagation_04.gif";
	img3off = new Image();
	img3off.src = "graphics/navagation_06.gif";	
	img4off = new Image();
	img4off.src = "graphics/navagation_08.gif";		
}
	
function imgOn(imgName) {
	if 	(document.images) {	
		document.images[imgName].src = eval(imgName + "on.src");
	}	
}	

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