Textbox valid:

If Not Isnull(This.Value) And This.Value <= Date()
   If Empty(Dtos(This.Value))
	Update CarsMemo SET Initials = Thisform.cUser
	This.Value = NULL
	DoDefault()
   Else
	Return 0
   Endif
Else
   Update CarsMemo SET Initials = Thisform.cUser
   DoDefault()
Endif

When saving I get the String data, right truncation error from the server.

So, why can't I set a datefield to null?

TIA