if (document.images) {



  img_nav_sub1_1on = new Image();

  img_nav_sub1_1on.src = "_images/nav_sub1_1over.gif";

  img_nav_sub1_2on = new Image();

  img_nav_sub1_2on.src = "_images/nav_sub1_2over.gif"; 

  

  img_nav_sub1_1off = new Image();

  img_nav_sub1_1off.src = "_images/nav_sub1_1off.gif";

  img_nav_sub1_2off = new Image();

  img_nav_sub1_2off.src = "_images/nav_sub1_2off.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");

    }

  }

}