var imageFiles_3f_21 = new Array();
imageFiles_3f_21['0'] = new Array ('_images/3f_Reptiles.gif', '_images/3f_ReptilesMouseover.gif');

function image_on_3f_21 (position) {
   var doc = eval("document.image3f_21" + position);
   doc.src = imageFiles_3f_21[position][1];
}

function image_off_3f_21 (position) {
   var doc = eval("document.image3f_21" + position);
   doc.src = imageFiles_3f_21[position][0];
}