var imageFiles_tb_1 = new Array();
imageFiles_tb_1['0'] = new Array ('_images/tb_ABOUT_US.gif', '_images/tb_ABOUT_USMouseover.gif');

function image_on_tb_1 (position) {
   var doc = eval("document.imagetb_1" + position);
   doc.src = imageFiles_tb_1[position][1];
}

function image_off_tb_1 (position) {
   var doc = eval("document.imagetb_1" + position);
   doc.src = imageFiles_tb_1[position][0];
}