use strict;
use warnings;
use Tk;

my $mw = MainWindow->new();
$mw->Label(
	-text => "Wait",
	-font => [-family => 'times', -size => 20],
)->pack(-expand => '1', -fill => 'both');
$mw->MainLoop;

doSomething($mw);#this is doing nothing here, it should be automatically called after creation and display of mainwindow

sub doSomething{
my $mw = shift;
print "Hello!\n";
$mw->destroy;
}