// JavaScript Document
function height_window(){ 
if(window.innerHeight) 
return window.innerHeight; 
if(document.body.clientHeight) 
return document.body.clientHeight; 
return (null); 
} 

var isIE=0; 
var isOtherBrowser=0; 
function pokus() { 
if(navigator.appName.indexOf('Microsoft Internet Explorer')!=-1) 
{isIE=1; 
var height_div=document.getElementById("container_index").scrollHeight; 
height=height_window(); 

document.getElementById('container_index').style.marginTop=(height-height_div)/2+'px'; 

} 
else 
{isOtherBrowser =1; 
var height_div= document.getElementById("container_index").scrollHeight; 
height=height_window(); 
document.getElementById('container_index').style.marginTop=(height-height_div)/2+'px'; 

zmena_okna = setTimeout("pokus()", 1); 

} 
}