//<!-- Ìõ·ù¹ö¶¯ -->
function showNav(){
if(window.screen.width<=800)
{
 document.getElementById("Nav04").style.display="none";
}
else
{
var heights = 10 + document.documentElement.scrollTop; 

document.getElementById("Nav04").style.top = heights+"px";
}
}
function Gun(){setInterval("showNav();",50)}
Gun();