if (navigator.appVersion.substring(0,1) >= 3) {
  button1_off = new Image;
  button1_off.src = "images/menu_button_normal.gif";
  button1_on  = new Image;
  button1_on.src  = "images/menu_button_hover.gif";
  button2_off = new Image;
  button2_off.src = "images/menu_button_normal.gif";
  button2_on  = new Image;
  button2_on.src  = "images/menu_button_hover.gif";
  button3_off = new Image;
  button3_off.src = "images/menu_button_normal.gif";
  button3_on  = new Image;
  button3_on.src  = "images/menu_button_hover.gif";
  button4_off = new Image;
  button4_off.src = "images/menu_button_normal.gif";
  button4_on  = new Image;
  button4_on.src  = "images/menu_button_hover.gif";
  button5_off = new Image;
  button5_off.src = "images/menu_button_normal.gif";
  button5_on  = new Image;
  button5_on.src  = "images/menu_button_hover.gif";
  button6_off = new Image;
  button6_off.src = "images/menu_button_normal.gif";
  button6_on  = new Image;
  button6_on.src  = "images/menu_button_hover.gif";
  button7_off = new Image;
  button7_off.src = "images/menu_button_normal.gif";
  button7_on  = new Image;
  button7_on.src  = "images/menu_button_hover.gif";
  button8_off = new Image;
  button8_off.src = "images/menu_button_normal.gif";
  button8_on  = new Image;
  button8_on.src  = "images/menu_button_hover.gif";
  button9_off = new Image;
  button9_off.src = "images/menu_button_normal.gif";
  button9_on  = new Image;
  button9_on.src  = "images/menu_button_hover.gif";
  button10_off = new Image;
  button10_off.src = "images/menu_button_normal.gif";
  button10_on  = new Image;
  button10_on.src  = "images/menu_button_hover.gif";
  button11_off = new Image;
  button11_off.src = "images/menu_button_normal.gif";
  button11_on  = new Image;
  button11_on.src  = "images/menu_button_hover.gif";
  button12_off = new Image;
  button12_off.src = "images/menu_button_normal.gif";
  button12_on  = new Image;
  button12_on.src  = "images/menu_button_hover.gif";
  button13_off = new Image;
  button13_off.src = "images/menu_button_normal.gif";
  button13_on  = new Image;
  button13_on.src  = "images/menu_button_hover.gif";
}

function navMouseOver(imgid,imgnew) {
 if (navigator.appVersion.substring(0,1) >= 3) {
   document.images[imgid].src=eval(imgnew + ".src");
 }
}