var imageFiles_4d_21 = new Array();
imageFiles_4d_21['0'] = new Array ('_images/4d_Components.gif', '_images/4d_ComponentsMouseover.gif');

function image_on_4d_21 (position) {
   var doc = eval("document.image4d_21" + position);
   doc.src = imageFiles_4d_21[position][1];
}

function image_off_4d_21 (position) {
   var doc = eval("document.image4d_21" + position);
   doc.src = imageFiles_4d_21[position][0];
}