if (document.images) {

    nav1 = new Image();
	nav1.src="/cow/i/menu_01_t.png";
    nav2 = new Image();
	nav2.src="/cow/i/menu_02_t.png";
    nav3 = new Image();
	nav3.src="/cow/i/menu_03_t.png";
    nav4 = new Image();
	nav4.src="/cow/i/menu_04_t.png";
    nav5 = new Image();
	nav5.src="/cow/i/menu_05_t.png";
    nav6 = new Image();
	nav6.src="/cow/i/menu_06_t.png";
	  nav7 = new Image();
	nav7.src="/cow/i/menu_07_t.png";
}


if (document.images) {

    nav1off = new Image();
	nav1off.src="/cow/i/menu_01.png";
    nav2off = new Image();
	nav2off.src="/cow/i/menu_02.png";
    nav3off = new Image();
	nav3off.src="/cow/i/menu_03.png";
    nav4off = new Image();
	nav4off.src="/cow/i/menu_04.png";
    nav5off = new Image();
	nav5off.src="/cow/i/menu_05.png";
    nav6off = new Image();
	nav6off.src="/cow/i/menu_06.png";
    nav7off = new Image();
	nav7off.src="/cow/i/menu_07.png";
}

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

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