hi,
thank you ,yes it works'
i'll try to change code at my form as your code.

>This works for me:
>

>oform = CREATEOBJECT('Test')
>oform.show
>READ EVENTS
>
>DEFINE CLASS test AS form
>
>	Top = 0
>	Left = 0
>	Height = 162
>	Width = 375
>	DoCreate = .T.
>	Caption = "Test Form"
>	Name = "Form1"
>
>
>	ADD OBJECT combo1 AS combobox WITH ;
>		Height = 24, ;
>		Left = 96, ;
>		Top = 96, ;
>		Width = 252, ;
>		Name = "Combo1"
>
>
>	ADD OBJECT text1 AS textbox WITH ;
>		Height = 23, ;
>		Left = 96, ;
>		ReadOnly = .T., ;
>		Top = 25, ;
>		Width = 144, ;
>		Name = "Text1"
>
>
>	ADD OBJECT label1 AS label WITH ;
>		AutoSize = .F., ;
>		BackStyle = 0, ;
>		Caption = "Alias", ;
>		Height = 17, ;
>		Left = 24, ;
>		Top = 29, ;
>		Width = 29, ;
>		Name = "Label1"
>
>
>	ADD OBJECT label2 AS label WITH ;
>		AutoSize = .F., ;
>		BackStyle = 0, ;
>		Caption = "Fields", ;
>		Height = 17, ;
>		Left = 24, ;
>		Top = 102, ;
>		Width = 36, ;
>		Name = "Label2"
>
>
>	ADD OBJECT text2 AS textbox WITH ;
>		Height = 23, ;
>		Left = 95, ;
>		ReadOnly = .T., ;
>		Top = 61, ;
>		Width = 253, ;
>		Name = "Text2"
>
>
>	ADD OBJECT label3 AS label WITH ;
>		AutoSize = .F., ;
>		BackStyle = 0, ;
>		Caption = "File", ;
>		Height = 17, ;
>		Left = 23, ;
>		Top = 65, ;
>		Width = 29, ;
>		Name = "Label3"
>
>
>	PROCEDURE Init
>		DODEFAULT()
>
>		this.addproperty("select_file",'')
>		LOCAL lcTable
>		lctable = GETFILE('DBF','Select a DBF') && Chose a dbf
>		IF !EMPTY(lctable)
>		   use (lctable) ALIAS mytable
>		   IF !EMPTY(ALIAS()) .or. DBF() = lctable
>			this.select_file = ALIAS()
>			this.AddProperty('my_fields[1]',.F.)
>			=AFIELDS(ThisForm.my_fields,JUSTSTEM(ThisForm.select_file))&& error at this line
>			ThisForm.combo1.RowSourceType = 5
>			ThisForm.combo1.RowSource = [ThisForm.my_fields]
>			ThisForm.combo1.Value     = ThisForm.my_fields[1]
>			ThisForm.combo1.Refresh()
>			ThisForm.Combo1.Interactivechange()
>			ThisForm.text1.value = JUSTSTEM(ThisForm.select_File)
>			Thisform.text2.value = DBF()
>		   ENDIF
>		ENDIF
>		RETURN .T.
>	ENDPROC
>
>	PROCEDURE Destroy
>		CLEAR EVENTS
>		DODEFAULT()
>	ENDPROC
>	
>	PROCEDURE text1.Refresh
>		this.disabledbackcolor = thisform.combo1.backcolor
>		DODEFAULT()
>	ENDPROC
>
>
>	PROCEDURE text2.Refresh
>		this.disabledbackcolor = thisform.combo1.backcolor
>		DODEFAULT()
>	ENDPROC
>
>
>ENDDEFINE
>