function createXMLHttpRequest() {
 
var ua;
 
if(window.XMLHttpRequest) {
    try {
      ua = new XMLHttpRequest();
    } catch(e) {
      ua = false;
    }
  } else if(window.ActiveXObject) {
    try {
      ua = new ActiveXObject('Microsoft.XMLHTTP');
    } catch(e) {
      ua = false;
    }
  }
  return ua;
}
 
var req = createXMLHttpRequest();
 
function sendRequest(digit,go,katid) {
  minus = digit-1;
  inhalt = document.getElementById('source' + minus );
  
  value_s1='NULL';
  value_s2='NULL';
  value_s3='NULL';
  value_s4='NULL';
  
  if(document.getElementById('source1')) { value_s1=document.getElementById('source1').value; }
  if(document.getElementById('source2')) { value_s2=document.getElementById('source2').value; }
  if(document.getElementById('source3')) { value_s3=document.getElementById('source3').value; }
  if(document.getElementById('source4')) { value_s4=document.getElementById('source4').value; }
  
  if(katid) { value_s1=katid; }
  
  if(digit == '99') {
  	document.getElementById('main').innerHTML = '<center><br><img src=\"sites/all/modules/kategorien/load.gif\"><br><br>Bitte warten. Daten werden geladen.<center>';
  	req.open('get', 'sites/all/modules/kategorien/request.php?dest='+ digit + '&s1=' + value_s1 + '&s2=' + value_s2 + '&s3=' + value_s3 + '&s4=' + value_s4 + '&go=' + go);
  }else {
  	req.open('get', 'sites/all/modules/kategorien/request.php?dest='+ digit + '&s=' + inhalt.value);
  }
  req.onreadystatechange = handleResponse;
  req.send(null);
}
 
function handleResponse() {
 
  if(req.readyState == 4){
    var response = req.responseText;
    var update = new Array();
 
    if(response.indexOf('||' != -1)) {
      update = response.split('||');
      document.getElementById(update[0]).innerHTML = update[1];
      if(update[0] == 'select2') {
      	document.getElementById('select3').innerHTML = '';
      	document.getElementById('select4').innerHTML = '';
      }
      if(update[0] == 'select3') {
      	document.getElementById('select4').innerHTML = '';
      }
      if(update[0] == 'select4') {
      }
      //alert(update[0]);
    }
  }
  //else
  //alert('loading' + ajax.readyState);
}