Problem in subroutine of SAP Script

Hi Experts,

I have defined one subroutine in the SAP script.

PERFORM Z_GET_PIC IN PROGRAM

USING &T001-BUKRS&

CHANGING &TEXT&

changing &TEXT& field i am populating from the table zmara and field is text (zmara-text).

so whether i have to define the &TEXT& in the SAP Script? how i have to define.

can i define like

DEFINE &TEXT&

Please suggest.

Regards,

udupi