function processRequest(){
  if (httpRequest.readyState == 4){
    if(httpRequest.status == 200){
      var div = document.getElementById('gbook');
      div.innerHTML = httpRequest.responseText;
    }
    else{
        alert("Chyba pri nacitani stranky"+ httpRequest.status +":"+ httpRequest.statusText);
    }
  }
}
function showForm(pid,parent){
    if (window.ActiveXObject)
        httpRequest = new ActiveXObject("Microsoft.XMLHTTP");
    else
        httpRequest = new XMLHttpRequest();

    httpRequest.open("GET", '/gbook.html?action=show&pid='+pid+'&parent='+parent, true);
    httpRequest.onreadystatechange= function () {processRequest(); } ;
    httpRequest.send(null);
}