jdporter, I think you may be missing the fine point of his question. It's about passing the button itself, in the format [\&callback,$val,'somedata']

I'm not exceptionally clear on why it has this effect, but look at the following example. Your way still dosn't pass the button object, while the second way does.

#!/usr/bin/perl
use warnings;
use strict; 
use Tk; 

my $mw = tkinit; 

my $push;   # dosn't work
$push = $mw->Button(-text => "test ",
           -command =>[\&save_parms,$push,'somedata']
            )->pack();


# works
my $push1 = $mw->Button(-text => "test1 ",
           )->pack();

$push1->configure( -command =>[\&save_parms,$push1,'somedata']);

MainLoop;

sub save_parms {
   print "@_\n";
}
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