Hello again,
you also didn't set the onClick attribute of '2 Fastest'.
I've modified the javascript slightly since you checked 2 Fastest by default. Clicking on any other checkbox will uncheck 2 Fastest now.

Depending on what you are going to do I'd possibly like to recommend some templating system like e.g. HTML::Template

For debugging javascript I use firebug with firefox. www.getfirebug.com

Greetings, michael

#!/usr/bin/perl -w

use strict; 
use diagnostics;
use Data::Dumper;

use CGI qw/:standard :html3/; 
use CGI::Carp qw( fatalsToBrowser );

my $JSCRIPT=<<EOF;
var twofastest;
var checkboxes=[];

function initVars(){
    if ( twofastest )
        return;

    twofastest = document.getElementById('2 Fastest');

    var cb = document.getElementsByName('progname');
    var b = 0;
    for (var a=0; a<cb.length; a++ ){
        if ( cb[a] != twofastest ){
            checkboxes[b] = cb[a];
            b++;
        }
    }

}

function checkBoxClick(){
    initVars();
    var anyboxchecked = false;
    for (var a=0; a<checkboxes.length; a++ ){
        if ( checkboxes[a].checked )
            anyboxchecked = true;
    }
    if ( anyboxchecked )
            twofastest.checked = false;

    twofastest.disabled = anyboxchecked;
}


function twofastestClick(){
    initVars();
    for (var a=0; a<checkboxes.length; a++ ){
            if ( twofastest.checked )
                checkboxes[a].checked = false;
            checkboxes[a].disabled = twofastest.checked;
    }
}
EOF

;

print header,
    start_html(
        -title => "Some Title",
        -script=> $JSCRIPT
    );

# some portions of code



sub generate_form {

    print start_multipart_form(),
        #strong('Your email: '),
        #textfield( -name => 'user_email' ), br, br


        strong('Basic Programs To Choose: '), br
        checkbox_group(
        -name   => 'progname',
        -values => [
            '2 Fastest',
            'MEME',
            'MITRA',
            'SPACE',
            ],
        -attributes=>{'2 Fastest'=>{'id'=>'2 Fastest', 'onClick'=>'two
+fastestClick()'},
                        MEME=>{onClick=>'checkBoxClick()' },
                        MITRA=>{onClick=>'checkBoxClick()' },
                        SPACE=>{onClick=>'checkBoxClick()' }
                }, #the extra line added to print id
        -rows => '2',
        -columns => '6',
        -defaults => [ '2 Fastest' ],
        ),
        p,
}



generate_form();

print end_html();
[download]

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