function setHeight() {
    var contentHeight = document.getElementById('rechts').offsetHeight;
    var browserHeight = document.body.clientHeight;
    
    //alert(browserHeight);
    
    document.getElementById('rechts').style.height = document.body.offsetHeight + 25 + 'px';
    
    if (browserHeight > contentHeight) {
        
        //alert(browserHeight + '>' + contentHeight);
    } else {
        //alert(browserHeight + '<' + contentHeight);
    }
}