function checkReservationdate(sender){
	var reservationdate = sender.value;
    var reservationHour = document.getElementById('reservationHour').value;
    return xajax_checkReservationDate(reservationdate,reservationHour);
}
function checkPersonnumber(sender){
	var objForm             = sender.form; 
    var personNumber        = sender.value;
    var reservationdate     = document.getElementById('reservationdate').value;
    var reservationArea     = checkRadioButton(objForm,'reservationArea');
    if(reservationArea == -1){
        alert("Bitte wählen Sie einen Bereich aus");
        return false;
    }   
    var reservationHour     = document.getElementById('reservationHour').value;
    var reservationMinute   = document.getElementById('reservationMinute').value;
    var reservationDateTime = reservationdate + " " + reservationHour + ":" + reservationMinute + ":00";
    return xajax_checkPersonnumber(reservationDateTime,personNumber,reservationArea);    
}