var imageFiles_4o5_1 = new Array();
imageFiles_4o5_1['0'] = new Array ('_images/4o5_More_From_Isaac_Newtons.gif', '_images/4o5_More_From_Isaac_NewtonsMouseover.gif');

function image_on_4o5_1 (position) {
   var doc = eval("document.image4o5_1" + position);
   doc.src = imageFiles_4o5_1[position][1];
}

function image_off_4o5_1 (position) {
   var doc = eval("document.image4o5_1" + position);
   doc.src = imageFiles_4o5_1[position][0];
}