var imageFiles_gn_1 = new Array();
imageFiles_gn_1['0'] = new Array ('_images/gn_Home.gif', '_images/gn_HomeMouseover.gif');
imageFiles_gn_1['1'] = new Array ('_images/gn_CT_Materials.gif', '_images/gn_CT_MaterialsMouseover.gif');
imageFiles_gn_1['2'] = new Array ('_images/gn_CWT_Materials.gif', '_images/gn_CWT_MaterialsMouseover.gif');
imageFiles_gn_1['3'] = new Array ('_images/gn_MCT_Materials.gif', '_images/gn_MCT_MaterialsMouseover.gif');

function image_on_gn_1 (position) {
   var doc = eval("document.imagegn_1" + position);
   doc.src = imageFiles_gn_1[position][1];
}

function image_off_gn_1 (position) {
   var doc = eval("document.imagegn_1" + position);
   doc.src = imageFiles_gn_1[position][0];
}