get value from PO header text in SAPScript

Hello all,

I am creating a PO form via transaction SE71.

In my PO form, I would like to add a logic to check if the PO header reference field have values or not.

To display the value, I have used the following script in the PO form:

INCLUDE &T166K-TXNAM& OBJECT &T166K-TDOBJECT& ID 'F02' LANGUAGE E PARAGRAPH Z1

where F02 is the field ID

Actually, Instead of displaying the value of the field, I would like to check whether the field have values or not?

Can I ask how is the script to perform this?

I have tried the follow:

IF INCLUDE &T166K-TXNAM& OBJECT &T166K-TDOBJECT& ID 'F02' LANGUAGE E PARAGRAPH Z1 NE SPACE

::::::::::::::::::

ENDIF

it failed.

Thanks

Sunny