As DamnDirtyApe has started to allude to, you cannot use a hyperlink to call a subroutine. A perl subroutine is encapsulated within the CGI process. An HTML hyperlink is simply another way of requesting a web "object", where an object can be any manner of hosted files... text/html, images, cgi scripts, etc. However, the execution of said scripts does NOT happen within Apache's process... a separate perl process is started to handle the cgi task; only the output of the script is returned to Apache for output to the requestor (browser).

Assuming you want the script to perform some function as defined by a subroutine, I suggest you create a URL with custom or hidden parameters, which, when read in by the cgi, understands to run the appropriate subroutine. Example:

#/usr/bin/perl -w

use strict;
use CGI qw(:standard);

my $cgi = CGI->new;

if ($cgi->param()) {
    if ($cgi->param('toggle_on')) {
        &toggle_on;
    } elsif ($cgi->param('toggle_off')) {
        &toggle_off;
    } else {
        &default;
    }
} else {
    # print form
    print $cgi->a({href => "/cgi-bin/script.cgi?toggle_on=1"}, "Toggle
+ On");
    # print more stuff
}
[download]

Hope this helps!

-fp