function setOrtVisibility() {
        var ort = document.freiForm.REISEN_kategorie.selectedIndex;
        if (ort == 0) {
                document.getElementById('inhaltort').style.display = 'none';
        } else {
                document.getElementById('inhaltort').style.display = 'block';
        }
}

function sendOrtRequest() {
        try {
                req = window.XMLHttpRequest?new XMLHttpRequest():
                new ActiveXObject("Microsoft.XMLHTTP");
        } catch (e) {
                //Kein AJAX Support
        }

        req.onreadystatechange = handleResponse;
        id = document.getElementById('REISEN_kategorie').value;
        req.open('get', '/freiplatz_ajax.php?p1='+ id);
        req.send(null);
}

function handleResponse() {
        if ((req.readyState == 4) && (req.status == 200)) {
                document.getElementById('inhaltort').innerHTML = req.responseText;
        }
}