function show(element) {
     var srcElement = document.getElementById(element);
    
     if(srcElement != null) {
        if(srcElement.style.display == "block") {
           srcElement.style.display= 'none';
        }
        else {
               srcElement.style.display='block';
        }
        return false; 
     }
    }
     
  function zmen() {
    if(document['obr'].src=='http://uploading.sk/images/vice.png') {
        document['obr'].src='http://uploading.sk/images/mene.png' 
        }                    
    else {
        document['obr'].src='http://uploading.sk/images/vice.png'
        }
                
}