Sap script - Incrementing Counter

Question

Hi all,
This is the code I have written in the main window of sap scrpt.
/: BOX FRAME 10 TW
/E MAIN
p3 &spaces(3)&&itab-carrid& &spaces(35)& &itab-connid&
= &spaces(25)&&itab-fldate&
/: PERFORM Z_V_SCRIPT IN PROGRAM Z_V_SCRIPT_SR
/: USING &COUNTER&
/: CHANGING &COUNTER&
/: ENDPERFORM
/: IF &COUNTER& EQ '1'
/: &ULINE(45)&
/: DEFINE &COUNTER& = 0
/: endif
This is the code for external subroutine z_v_script_sr.
REPORT  Z_V_SCRIPT_SR.
FORM z_v_script TABLES  IN_PAR STrUCTURE ITCSY
                      OUT_PAR STRUCTURE ITCSY.
data : cntr type i value  -1.
data : ch(3) type c.
read table in_par with key 'COUNTER'.
if sy-subrc = 0.
cntr = in_par-value.
endif.
cntr =  cntr + 1.
ch  = cntr.
read table out_par with key 'COUNTER'.
if sy-subrc = 0.
out_par-value = ch.
endif.
MODIFY OUT_PAR INDEX SY-TABIX.
write : 'vijay'.
endform.
I do not understand where I am going wrong.If I debug the subroutine the value of counter is being changed to 1 but it is not reflected when I debug my script. Please explain me where I am going wrong.
Regards,
Varun

Answer 1

You counter must be held in global memory, otherwise it will always be the same.  PUt the data statement at the top of your print program.  Having it defined in the routine, means that everytime the routine is fired, it will be that value. In this case -1.
data : cntr type i value -1.
ALso, comment out the USING line in the SAPscript.
/: PERFORM Z_V_SCRIPT IN PROGRAM Z_V_SCRIPT_SR
<b>/* USING &COUNTER&</b>
/: CHANGING <b>&COUNTER&</b>
/: ENDPERFORM
/: IF &COUNTER& EQ '1'
/: &ULINE(45)&
/: DEFINE &COUNTER& = 0
/: endif
Also shouldn't the counter field be defined in the print program as well.   
Is COUNTER defined in the print program?
Regards,
Rich Heilman