var imageFiles_z_4 = new Array();
imageFiles_z_4['0'] = new Array ('_images/z_Anatomy.gif', '_images/z_AnatomyMouseover.gif');
imageFiles_z_4['1'] = new Array ('_images/z_FAQ.gif', '_images/z_FAQMouseover.gif');

function image_on_z_4 (position) {
   var doc = eval("document.imagez_4" + position);
   doc.src = imageFiles_z_4[position][1];
}

function image_off_z_4 (position) {
   var doc = eval("document.imagez_4" + position);
   doc.src = imageFiles_z_4[position][0];
}