use strict;
use Tk;

my $mw = MainWindow->new;

my $hello_string = "Hello";
my $silly_string = "Very Silly!!!";


my $frame1 = $mw->Frame();    
my $frame2 = $mw->Frame();     
my $frame3 = $mw->Frame();
my $frame4 = $mw->Frame();   

my %frame_var_hash = 
          ($frame1 => {-text => $hello_string, width => 7}, 
           $frame2 => {-text => $silly_string, width => 9}, 
           $frame3 => {-text => "XXXXX",       width => 35},
           $frame4 => {-text => $silly_string, width => 7});

 
foreach my $cur_frame (keys %frame_var_hash){
    
    $cur_frame->Label(
		      $frame_var_hash{$cur_frame},
		      -expand => 1,
		      )->pack();
}
[...]
MainLoop;