PO Form Issue with Header Level Changes

Question

Issue:
It has been observed that whenever changes are done in PO Header (e.g. Header Text), system prints Billing Address and Communications Details as blank. If the changes are made to Line Item level along with header then system prints the Billing address and Communication Details correctly.
Analyse:
we are using the SELECT statement below to fetch the field for
Billing Address and Communications Details.
SELECT SINGLE
mandt z_plant z_company_code z_toll_free_no z_local_no z_fax_no
z_email z_name1 z_name2 z_street z_house_no z_district z_post_code
z_city z_country z_vat_no z_loc_term_cond z_langu
  FROM zptp_poformdata
  INTO w_poformdata
  WHERE z_plant = ls_ekpo-werks
AND   z_company_code = ls_ekpo-bukrs .  
And when we only change the header level  data no value is passing for comany code and plant . as a result Select statement gets failed and we are getting blank window.
NOTE: we are getting blank box only when we fire a print or fax.The preview is coming fine.

Answer 1

by asking so many questions in a single post,you are violating the rule of engagement given below
Only One Question Per Posting
For each question that you have, make a separate posting. Don't ask multiple questions in one posting, this is confusing for people and might not get answered, since the subject line does not reflect all your problems. If a new and unrelated question comes up during a thread, start a new thread.