var img1 = new Image(); img1.src='/images/nav1_on.jpg';
var img2 = new Image(); img2.src='/images/nav2_on.jpg';
var img3 = new Image(); img3.src='/images/nav3_on.jpg';
var img4 = new Image(); img4.src='/images/nav4_on.jpg';
var img5 = new Image(); img5.src='/images/nav5_on.jpg';
var img6 = new Image(); img6.src='/images/nav6_on.jpg';