var imageFiles_a_4 = new Array();
imageFiles_a_4['0'] = new Array ('_images/a_Home__.gif', '_images/a_Home__Mouseover.gif');
imageFiles_a_4['1'] = new Array ('_images/a_About_Us__.gif', '_images/a_About_Us__Mouseover.gif');
imageFiles_a_4['2'] = new Array ('_images/a_Feedback__.gif', '_images/a_Feedback__Mouseover.gif');
imageFiles_a_4['3'] = new Array ('_images/a_Contact_Us.gif', '_images/a_Contact_UsMouseover.gif');

function image_on_a_4 (position) {
   var doc = eval("document.imagea_4" + position);
   doc.src = imageFiles_a_4[position][1];
}

function image_off_a_4 (position) {
   var doc = eval("document.imagea_4" + position);
   doc.src = imageFiles_a_4[position][0];
}