var imageFiles_is_1 = new Array();
imageFiles_is_1['0'] = new Array ('_images/is_EXISS.gif', '_images/is_EXISSMouseover.gif');

function image_on_is_1 (position) {
   var doc = eval("document.imageis_1" + position);
   doc.src = imageFiles_is_1[position][1];
}

function image_off_is_1 (position) {
   var doc = eval("document.imageis_1" + position);
   doc.src = imageFiles_is_1[position][0];
}