function onClickTripType() {
  //alert("onClickTripType() called");
  var formQuery = document.getElementById ? document.getElementById("formQuery") : formQuery;
  //alert("formQuery="+formQuery);
  //alert("formQuery.tripType="+formQuery.tripType);  
  //alert("formQuery.tripType.values="+formQuery.tripType.values);
  if(formQuery.tripType[0].checked) { // one way
    hiddenReturnDate();
  }
  else {
    showReturnDate();
  }
  //alert("onClickTripType() end");
}

function showReturnDate() {
  //alert("showReturnDate() called");
  var retDateRow = document.getElementById("retRow");
  retDateRow.style.display = "";
  //alert("showReturnDate() end");
}

function hiddenReturnDate() {
  //alert("hiddenReturnDate() called");
  var retDateRow = document.getElementById("retRow");
  retDateRow.style.display = "none";
  //alert("hiddenReturnDate() end");
}