Roberto and Larry,

Having the calendar form make changes to the calling form's properties is a bad design. The calendar form should not be changing anything in the callinf form. Instead use a parameter objerct that is passed to the calendar form as in;

* ParamObj.prg
DEFINE CLASS ParamObj AS Relation

PROCEDURE Init
   This,addproperty('RetArray(1)',"")
   DIMENSION This.RetArray(1,2)
   This.RetArray = ""
   RETURN
ENDPROC

ENDDEFINE

Now when you call the calendar;

* some method in the calling form
loParam = NewObject("ParamObj","ParamObj.prg")
DO FORM Calendar WITH loParam
ldMyDate =  loParam.RetArray(1,1)
* Now do what you need with the date.
RETURN

Here's the code inside of the Calendar form;

* Calendar form Init
LPARAMETERS poParams
This.AddProperty("oParams",poParams)

And later in the calendar form's Destroy

* Calendar form's Destroy
This.oParams.RetArray(1,1) = This.Date
RETURN

Do this this way removes any dependance of the claendar form from the form that is calling it. All manipulation is done to ther parameter object that is being passed around. The technique can be expanded to have the calling form put values in the parameter object that the calendar form reads for information and then teh calendar form posts the results in the same parameter object. This technique removes the issue of the calendar form making chang4es directly to the form that called it and it removes the whole garbage about hiding the clasendar and leter destroying it (or forgetting to and leaving the calendar hanging around taking up memory).