if (document.images) {
  var menu1up = new Image();
  menu1up.src = "menu_images/button1.gif";
  var menu1down = new Image();
  menu1down.src = "menu_images/button1_rl.gif";
  
  var menu2up = new Image();
  menu2up.src = "menu_images/button2.gif";
  var menu2down = new Image();
  menu2down.src = "menu_images/button2_rl.gif";
 
  var menu3up = new Image();
  menu3up.src = "menu_images/button3.gif";
  var menu3down = new Image();
  menu3down.src = "menu_images/button3_rl.gif";
  
  var menu4up = new Image();
  menu4up.src = "menu_images/button4.gif";
  var menu4down = new Image();
  menu4down.src = "menu_images/button4_rl.gif";
  
  var menu5up = new Image();
  menu5up.src = "menu_images/button5.gif";
  var menu5down = new Image();
  menu5down.src = "menu_images/button5_rl.gif";

  var menu6up = new Image();
  menu6up.src = "menu_images/button6.gif";
  var menu6down = new Image();
  menu6down.src = "menu_images/button6_rl.gif";

  var menu7up = new Image();
  menu7up.src = "menu_images/button7.gif";
  var menu7down = new Image();
  menu7down.src = "menu_images/button7_rl.gif";

}

function act(imgName) {
  if (document.images) 
    document[imgName].src = eval(imgName + "down.src"); 
}

function inact(imgName) {
  if (document.images)
    document[imgName].src = eval(imgName + "up.src");
}