Hi I am trying to execute the following PB code

declare f_check procedure for p_check
(
vc_startnum = :ls_start_num,
vc_stopnum = :ls_stop_num
);
execute f_check;

I am using Informix ODBC driver. I am getting a SQLERRTEXT as
"Systax Error"

Does anybody have a clue why I am getting it?
Thanks