if (document.images) {

  img_nav_main_1on = new Image();
  img_nav_main_1on.src = "_img/nav_main1over.gif";
  img_nav_main_2on = new Image();
  img_nav_main_2on.src = "_img/nav_main2over.gif"; 
  img_nav_main_3on = new Image();
  img_nav_main_3on.src = "_img/nav_main3over.gif";
  img_nav_main_4on = new Image();
  img_nav_main_4on.src = "_img/nav_main4over.gif";
  img_nav_main_5on = new Image();
  img_nav_main_5on.src = "_img/nav_main5over.gif";
  img_nav_main_6on = new Image();
  img_nav_main_6on.src = "_img/nav_main6over.gif";
  img_nav_main_7on = new Image();
  img_nav_main_7on.src = "_img/nav_main7over.gif";

  img_nav_main_1off = new Image();
  img_nav_main_1off.src = "_img/nav_main1off.gif";
  img_nav_main_2off = new Image();
  img_nav_main_2off.src = "_img/nav_main2off.gif";
  img_nav_main_3off = new Image();
  img_nav_main_3off.src = "_img/nav_main3off.gif";
  img_nav_main_4off = new Image();
  img_nav_main_4off.src = "_img/nav_main4off.gif";
  img_nav_main_5off = new Image();
  img_nav_main_5off.src = "_img/nav_main5off.gif";
  img_nav_main_6off = new Image();
  img_nav_main_6off.src = "_img/nav_main6off.gif";
  img_nav_main_7off = new Image();
  img_nav_main_7off.src = "_img/nav_main7off.gif";


  img_learnmore_1on = new Image();
  img_learnmore_1on.src = "_img/b_learnmore_over.gif";
  
  img_learnmore_1off = new Image();
  img_learnmore_1off.src = "_img/b_learnmore_off.gif";

}

function changeImages() {
  if (document.images) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = eval(changeImages.arguments[i+1] + ".src");
    }
  }
}