use strict; 
use Tk;   

my $main = MainWindow->new;

$main->minsize(qw(350 350));
$main->title("GUI");
$main->configure();
	
my $left3 = $main->Frame()->pack(-side=>'left');  
      	
my $padchk=0;
if ($padchk==1) {$padchk=1;}
else {$padchk=0;}
	
my $padchk = $left3->Checkbutton(-variable=>\$padchk,-command=> sub{open_menu($padchk)})->pack(); 
	
MainLoop; 

sub open_menu {
my $padchk= shift;
my $gdsPath= shift;
my $text=$left3->Label(-text=> 'enter your name:', -background=>'white');
my $gdsPath=$left3->Entry();

if ($padchk==1){

$text->pack();
$gdsPath->pack();
}

elsif ($padchk==0){
$text->destroy;
$gdsPath->destroy;
$left3->update;
}
}