var imageFiles_n_31 = new Array();
imageFiles_n_31['0'] = new Array ('_images/n_Metals.gif', '_images/n_MetalsMouseover.gif');
imageFiles_n_31['1'] = new Array ('_images/n_Transferware.gif', '_images/n_TransferwareMouseover.gif');
imageFiles_n_31['2'] = new Array ('_images/n_Oz_Books.gif', '_images/n_Oz_BooksMouseover.gif');
imageFiles_n_31['3'] = new Array ('_images/n_Ruth_R__Cummings.gif', '_images/n_Ruth_R__CummingsMouseover.gif');

function image_on_n_31 (position) {
   var doc = eval("document.imagen_31" + position);
   doc.src = imageFiles_n_31[position][1];
}

function image_off_n_31 (position) {
   var doc = eval("document.imagen_31" + position);
   doc.src = imageFiles_n_31[position][0];
}