HOW TO SET MY OWN PF-STATUS-urgent

hi all,

anybody can tell me where i made mistake . after writing this code when i am running this report it is not showing our own pf-staus.

report zmahi4.

selection-screen: begin of block b1.

parameters : p_appln type zuser_secobjects-appln.

parameters : p_user type zuser_secobjects-appln_user.

selection-screen end of block b1.

data : exclude like rsexfcode occurs 0 with header line.

at selection-screen output.

call function 'RS_SET_SELSCREEN_STATUS'

exporting

p_status = 'SELK'

tables

p_exclude = exclude

exceptions

others = 1.

thanks,

maheedhar.t