function sendRequest() {
  if (navigator.appName == "Microsoft Internet Explorer") {
    id = document.getElementById('vbmembermap_plz').value;
    land = document.getElementById('vbmembermap_land').value;
  } else {
    id = document.forms['vbmembermap_userstats'].elements['vbmembermap_plz'].value;
    land = document.forms['vbmembermap_userstats'].elements['vbmembermap_land'].value;
  }
  DoAjax = new vB_AJAX_Handler (true);
  DoAjax.onreadystatechange (getRequested);
  DoAjax.send ('vbmembermap.php', 'do=ajax&splz='+id+'&land='+land);
}

function getRequested() {
   if (DoAjax.handler.readyState == 4) {
     document.getElementById('inhalt').innerHTML = DoAjax.handler.responseText;
   }
}