How to stop manual entry in the date field

hello, is there any way to stop manual entry from user in the date field. I have one form where there are some date fields. Basis on these dates reports are getting downloaded.problem is that some users are giving manula entry in these date fields which is creating confusion while downloading report.

                        Kindly suggest the way to stop this and enforce users to use only calender that comes in the date field.

Thanks in advance

Subject: How to stop manual entry in the date field

copy the below lotusscript code in ‘Onfocus’ event of the date field.It would wash out manual entry by user but selection from date calendar wont be wiped.

Sub Onfocus(Source As Field)

Dim ws As New NotesUIWorkspace

Dim uidoc As NotesUIDocument

Set uidoc=ws.CurrentDocument



uidoc.document.Source=""	

End Sub