function ShowKalenderForTextfield(atxtfldid) {
   var pos = CalcElementPositionId(atxtfldid);
   CAL_ON_CHOOSE_DATE = function(date) {
      var el_datum = GetElement(atxtfldid);
      el_datum.value = date;
      el_datum.focus();
      Calendar_Hide();
   };      
   var date = new Date();
   var value = GetFieldValue(atxtfldid);
   if (value != '') {
      date.FromFMSDate(value);
   }
   Calendar_Show(date.getFullYear(), date.getMonth() + 1, pos[0], pos[1]);
}