working = false;

// initialize the ajax engine
function ajax_init() {
  http_request = false;

  /*@cc_on @*/
  /*@if (@_jscript_version >= 5)

  try { http_request = new ActiveXObject("Msxml2.XMLHTTP"); } 
  catch (e) { try { http_request = new ActiveXObject("Microsoft.XMLHTTP"); } 
  catch (E) { http_request = false; } }

  @end @*/

  if (!http_request && typeof XMLHttpRequest!='undefined') {
    http_request = new XMLHttpRequest();
  }
  
  if (!http_request) { alert("Az ön böngészője nem támogatja az ajax kommunikációt, sajnáljuk!"); }
}

// getting a page via ajax
function ajax_get(page) {
  if (working != true ) {
    ajax_init();
    working = true;

    document.getElementById("street").innerHTML = '<select name="utca" size="1"><option value=0>kérem, várjon</option></select>';

    http_request.onreadystatechange = ajax_work;
    http_request.open("GET","streets/"+page+".txt", true);
    http_request.setRequestHeader("Connection", "close");
    http_request.send(null);
  }
}

// waiting for ajax, to ready state
function ajax_work() {
  if (http_request.readyState == 4) {
    var szoveg = http_request.responseText; if ( szoveg == "" ) { szoveg = '<option value=0>Nincs megjeleníthető elem</option>'; }
    document.getElementById("street").innerHTML = '<select name="user_utca" size="1">'+szoveg+'</select>';
    working = false;
  }
}