As i've mentioned, the call to the second subroutine (changewebpass) where a module HTTP::Request::Common is called again fails because the $postdata which is supposed to contain $all_ap{$_}->{'webadminpostdata'} gets emptied after calling the first sub (loginweb) where that module is called the first time. before calling the loginweb sub, I can easily print $all_ap{$_}->{'webadminpostdata'} or access any of its members/field. This is really weird. I wanted to debug it, but I haven't done any debugging before. I wanted to but I'm having a hard time reproducing the code in a smaller dummy program. Any more idea? Btw, i've checked that my syntax is correct, passing hash reference to that module's sub routine. I've also tried putting the creation of 'webadminpostdata' right after the call to login and the program runs fine.