var browserName=navigator.appName;
 IE = false;
 if (browserName=="Microsoft Internet Explorer") { IE=true;} 
 
 var vyska_obsahu=1;
 
 function getInsideWindowHeight( ) {
    var isIE6CSS = (document.compatMode && document.compatMode.indexOf("CSS1") >= 0) ? true : false;
    if (window.innerHeight) {
        return window.innerHeight;
    } else if (isIE6CSS) {
        // measure the html element's clientHeight
        return document.body.parentElement.clientHeight;
    } else if (document.body && document.body.clientHeight) {
        return document.body.clientHeight;
    }
    return 0;
}