myFrm=Createobject("My_Form")
myFrm.Show( 1 )

Define Class My_Form As Form
	Procedure Init
		Create Cursor tmp(fld_char c( 10 ) Null)
		INSERT INTO tmp(fld_char) values(.Null.)
	
		This.AddObject("MyTxt","Textbox")
		This.MyTxt.Controlsource='tmp.fld_char'
		*This.MyTxt.NullDisplay="aaaaaaaaaaaaaaa"
		This.MyTxt.Visible=.T.
	Endproc
Enddefine

myFrm=Createobject("My_Form")
myFrm.Show( 1 )
USE IN tmp

Define Class My_Form As Form
	Procedure Init
		Create Cursor tmp(fld_char c( 10 ) Null,fld_2 C( 10 ))
		INSERT INTO tmp(fld_char,fld_2) values(.Null.,"first")
		INSERT INTO tmp(fld_char,fld_2) values("It's not NULL","second")
		INSERT INTO tmp(fld_char,fld_2) values(.Null.,"third")
		GO top
		
		This.AddObject("MyGrd","Grid")
		This.MyGrd.ColumnCount=0
		This.MyGrd.RowHeight=30
		This.MyGrd.AddObject('my_Col1','my_Column')
		This.MyGrd.AddObject('my_Col2','my_Column')
		This.MyGrd.Visible=.T.

		This.MyGrd.RecordSource="tmp"
		This.MyGrd.RecordSourceType=1
	Endproc
Enddefine

Define Class my_Column As Column
	Sparse=.F.
	Visible = .T.
	Procedure Init
		This.RemoveObject('Text1')
		This.AddObject('MyTxt','My_Text')
	Endproc
Enddefine

Define Class My_Text As Textbox
	Procedure Init
		this.NullDisplay="It's NULL"
	Endproc
ENDDEFINE