use warnings;
use strict;

my %dispatch = ( foo => \&foo, bar => \&bar );

$dispatch{foo}->("here we go!");
my $key = "bar";
$dispatch{$key}->("another message");

sub foo
{
   my $arg = shift;
   print "foo: $arg\n";
}

sub bar
{
   my $arg = shift;
   print "bar: $arg\n";
}
__END__
foo: here we go!
bar: another message