arImageSrc = new Array (
"images/na.cu.on.jpg",
"images/nav.agh.on.jpg",
"images/nav.eo.on.jpg",
"images/nav.re.on.jpg",
"images/nav.pr.on.jpg"
)

arImageList = new Array ();

for (counter in arImageSrc) {
arImageList[counter] = new Image();
arImageList[counter].src = 
arImageSrc[counter];
}