my $boom;

sub die
{ 
    $boom = MainWindow->new( -background=>'green'); # this is where local was
    my $label = $boom->Label(); 
    my $yes = $boom->Button(); 
    my $no = $boom->Button(); 
    $label->configure(-text=>'DO you really want to quit?'); 
    $yes->configure(-text=>'Yes',-command=>\&des); 
    $no->configure(-text=>'NO', -command=>\&goback); 
    $label->pack(); 
    $yes->pack(); 
    $no->pack(); 
} 

sub goback
{ 
    $boom->packForget(); 
} 

sub des
{ 
    $boom->packForget(); 
}

##</code><code>##

die; # creates window 1
die; # creates window 2