v=parseInt(navigator.appVersion.substring(0,1));

  if (v>=3) for (i=1; i<=7; i++) {

    image=new Image();

    image.src="images/mainmenu"+i+".gif";

  }

  function mshow(what){

    if (v>=3) document.mainmenu.src="images/mainmenu"+what+".gif";

  }

  function mhide(){

    if (v>=3) document.mainmenu.src="images/mainmenu.gif";

  }