>Hi,
>I want to control user to enter client code in a editbox and not allow enter a blank client code, if user enter a blank field, an warning message will display and setfocus to the editbox, I put the checking code in the Lostfocus event of the editbox, the code as follow:-
>

>SET EXACT ON
>IF SEEK(ALLTRIM(thisform.txtCusno.Value),"CUSMAS")
>   thisform.txtCusname.Value = cusmas->cusname
>ELSE
>	IF EMPTY(thisform.txtCusno.Value)
>		MESSAGEBOX("You must enter client code!",48,"Warning")
>	ELSE
>		MESSAGEBOX("Client code not exist!",48,"Warning")
>	ENDIF
>   	thisform.txtCusname.Value = " "
>	thisform.txtCusno.SetFocus()
>ENDIF
>
>

>When user press TAB to bypass the input, I find that thisform.txtCusno.SetFocus() does not work. I try to put this checking into the VALID event, but the VALID event does not allow the setfocus statement.
>How could I do? please suggest.
>
>Thanks
>
>Derek Yim

Try:

SET EXACT ON
IF SEEK(ALLTRIM(thisform.txtCusno.Value),"CUSMAS")
   thisform.txtCusname.Value = cusmas->cusname
ELSE
	IF EMPTY(thisform.txtCusno.Value)
		MESSAGEBOX("You must enter client code!",48,"Warning")
	ELSE
		MESSAGEBOX("Client code not exist!",48,"Warning")
	ENDIF
   	thisform.txtCusname.Value = " "
	thisform.txtCusno.SetFocus()
        NODEFAULT
        RETURN
ENDIF