#!perl -w
use strict;
use CGI;
use Data::Dumper;

sub do_foo {
    my( %params )= @_;
    print Dumper \%params;
    if( $params{ is_admin }) {
        print "Is admin\n";
    } else {
        print "No admin\n";
    };
};

my $q= CGI->new();
do_foo( is_admin => 0, foo => $q->param('foo') );

##</code><code>##

perl -w test.pl foo=1
perl -w test.pl foo=bar
perl -w test.pl foo=0&foo=is_admin&foo=yeah&foo=another_parameter&foo=yippieh