if (document.images) {
	var img = new Array();
	//enter images into the array
	img[0] = 'images/home_0.gif';
	img[1] = 'images/home_1.gif';
	img[2] = 'images/nav_about_0.gif';
	img[3] = 'images/nav_about_1.gif';
	img[4] = 'images/nav_fixtures_0.gif';
	img[5] = 'images/nav_fixtures_1.gif';
	img[6] = 'images/nav_tooling_0.gif';
	img[7] = 'images/nav_tooling_1.gif';
	img[8] = 'images/nav_production_0.gif';
	img[9] = 'images/nav_production_1.gif';
	img[10] = 'images/nav_machines_0.gif';
	img[11] = 'images/nav_machines_1.gif';
	img[12] = 'images/nav_gauging_0.gif';
	img[13] = 'images/nav_gauging_1.gif';
	img[14] = 'images/nav_contact_0.gif';
	img[15] = 'images/nav_contact_1.gif';
	img[16] = 'images/nav_engineering_0.gif';
	img[17] = 'images/nav_engineering_1.gif';
	img[18] = 'images/nav_catalogue_0.gif';
	img[19] = 'images/nav_catalogue_1.gif';
				
	var im = new Array();
	
	for (var i = 0; i < img.length; i++) {
		im[i] = new Image();
		im[i].src = img[i];	
	}
}

function toggleImg(imageName, num) {
	if (document.images) {
		document.images[imageName].src = im[num].src;
	}
}