jQuery.preloadImages = function()
{
  for(var i = 0; i<arguments.length; i++)
  {
    jQuery("<img>").attr("src", arguments[i]);
  }
}

$(document).ready(function(){ 
    $(document).pngFix();
    
    $.preloadImages(
        "img/nav/on_button_home.gif", 
        "img/nav/on_button_exhibition.gif",
        "img/nav/on_button_audio.gif",
        "img/nav/on_button_design.gif",
        "img/nav/on_button_photo.gif",
        "img/nav/on_button_motion.gif",
        "img/nav/on_button_projects.gif",
        "img/nav/on_button_info.gif",
        "img/nav/on_button_home_de.gif", 
        "img/nav/on_button_exhibition_de.gif",
        "img/nav/on_button_audio_de.gif",
        "img/nav/on_button_design_de.gif",
        "img/nav/on_button_photo_de.gif",
        "img/nav/on_button_motion_de.gif",
        "img/nav/on_button_projects_de.gif",
        "img/nav/on_button_info_de.gif"
    );
     
});