imgsrc = new Array();

imgsrc[1] = "images/mnu_top1.gif";
imgsrc[2] = "images/mnu_top2.gif";
imgsrc[3] = "images/mnu_pro1.gif";
imgsrc[4] = "images/mnu_pro2.gif";
imgsrc[5] = "images/mnu_sch1.gif";
imgsrc[6] = "images/mnu_sch2.gif";
imgsrc[7] = "images/mnu_rec1.gif";
imgsrc[8] = "images/mnu_rec2.gif";
imgsrc[9] = "images/mnu_dia1.gif";
imgsrc[10] = "images/mnu_dia2.gif";

img = new Array();

for (i=0; i < imgsrc.length; i++) {
     img[i] = new Image();
     img[i].src = imgsrc[i];
     }

function rollover(num, imgname) {
     document.images[imgname].src = img[num].src;
     }

function rollout(num, imgname) {
     document.images[imgname].src = img[num].src;
     }