<!-- common.js, most common javascript functions -->
function changeImage(t_imageName,t_url,t_layer) {
    NS4 = (document.layers) ? 1 : 0;
    if((t_layer!='')&&(NS4)) {
        document.layers[t_layer].document[t_imageName].src=t_url;
    }
    else
        document.images[t_imageName].src=t_url;

}