Image1= new Image(121,120);
Image1.src = "images/homeBtnHover.gif";

Image2 = new Image(121,120);
Image2.src = "images/shoppingBtnHover.gif";

Image3 = new Image(121,120);
Image3.src = "images/customerCreateBtnHover.gif";

Image4 = new Image(121,120);
Image4.src = "images/contactBtnHover.gif";

Image5 = new Image(121,120);
Image5.src = "images/aboutBtnHover.gif";

function rollover(imageID, image)
{
    document.getElementById(imageID).src = image;
}