function newImage(arg) {
if (document.images) {
rslt = new Image();
rslt.src = arg;
return rslt;
}
}

function changeImages() {
if (document.images && (preloadFlag == true)) {
for (var i=0; i<changeImages.arguments.length; i+=2) {
document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
}
}
}

var preloadFlag = false;
function preloadImages() {
if (document.images) {
shell7_01_13_over = newImage("images/shell7_01_13_over.gif");
shell7_04_14_over = newImage("images/shell7_04_14_over.gif");
shell7_07_15_over = newImage("images/shell7_07_15_over.gif");
shell7_08_16_over = newImage("images/shell7_08_16_over.gif");
shell7_09_17_over = newImage("images/shell7_09_17_over.gif");
shell7_10_18_over = newImage("images/shell7_10_18_over.gif");
shell7_11_19_over = newImage("images/shell7_11_19_over.gif");
preloadFlag = true;
}
}