function preloader(){
    document.getElementById('preloader').style.display = 'none';
    document.getElementById('wrapper').style.visibility = 'visible';
    document.getElementById('menu').style.visibility = 'visible';
    document.getElementById('sub_menu').style.visibility = 'visible';
}
if(window.addEventListener){window.addEventListener('load', preloader, false);}
else{window.attachEvent('onload', preloader);}