var imageFiles_y_4 = new Array();
imageFiles_y_4['0'] = new Array ('_images/y_GET_GIFT_CERTIFICATES.gif', '_images/y_GET_GIFT_CERTIFICATESMouseover.gif');

function image_on_y_4 (position) {
   var doc = eval("document.imagey_4" + position);
   doc.src = imageFiles_y_4[position][1];
}

function image_off_y_4 (position) {
   var doc = eval("document.imagey_4" + position);
   doc.src = imageFiles_y_4[position][0];
}