#This creates the widget and place it: my $Entry2 = $mw->Entry( -relief => "sunken" ); $Entry2->place( -x => 88, -y => 33, -height => 16, -width => 120); # And I have a button that calls the sub that does the trick: my $Button3 = $mw->Button( -text => "Cadastrar", -relief => "raised", -command => \&add ); $Button3->place( -x => 218, -y => 33, -height => 16, -width => 56); # The above parts works as expected, my problem lies below (notice that the snippet below is, obviously, after the MainLoop): sub add { my $name = $Entry2->get(0.1, 'end'); my $file = "data.dat"; open(CLIST, "+>>$file"); flock(CLIST,2); print CLIST $name."\n"; flock(CLIST,8); close($file); }