var imageFiles_50_400 = new Array();
imageFiles_50_400['0'] = new Array ('_images/50_Product_Catalog.gif', '_images/50_Product_CatalogMouseover.gif');

function image_on_50_400 (position) {
   var doc = eval("document.image50_400" + position);
   doc.src = imageFiles_50_400[position][1];
}

function image_off_50_400 (position) {
   var doc = eval("document.image50_400" + position);
   doc.src = imageFiles_50_400[position][0];
}