var imageFiles_3is_1 = new Array();
imageFiles_3is_1['0'] = new Array ('_images/3is_Cirlce_J_Trailers.gif', '_images/3is_Cirlce_J_TrailersMouseover.gif');
imageFiles_3is_1['1'] = new Array ('_images/3is_PJ_Trailers.gif', '_images/3is_PJ_TrailersMouseover.gif');
imageFiles_3is_1['2'] = new Array ('_images/3is_Tractor_Attachments.gif', '_images/3is_Tractor_AttachmentsMouseover.gif');

function image_on_3is_1 (position) {
   var doc = eval("document.image3is_1" + position);
   doc.src = imageFiles_3is_1[position][1];
}

function image_off_3is_1 (position) {
   var doc = eval("document.image3is_1" + position);
   doc.src = imageFiles_3is_1[position][0];
}