here's (part of) my code:
my $but1 = $mw -> Button(-text => "1", -command =>\&push_1)->pack(-side => 'left');
my $but2 = $mw -> Button(-text => "2", -command =>\&push_2)->pack();
my $but3 = $mw -> Button(-text => "3", -command =>\&push_3)->pack(-side => 'right');
how do i align all the buttons...