var imageFiles_ch_15 = new Array();
imageFiles_ch_15['0'] = new Array ('_images/ch_Home.gif', '_images/ch_HomeMouseover.gif');

function image_on_ch_15 (position) {
   var doc = eval("document.imagech_15" + position);
   doc.src = imageFiles_ch_15[position][1];
}

function image_off_ch_15 (position) {
   var doc = eval("document.imagech_15" + position);
   doc.src = imageFiles_ch_15[position][0];
}