Welcome to WebmasterWorld, Maruthi.

Perl subroutines run on the server-side whereas the onclick attribute of an element is a client-side action. The only way to run a perl subroutine on the server on an onclick attribute would be to fetch the request from the server.

I'm not sure if this is what you want but you can essentially do this using XMLHttpRequest (AJAX):
[perl.com...]

Also, this was written for PHP but you can just as easily use it for perl:
Rasmus Lerdorf (creator of PHP) 30 second AJAX Tutorial [news.php.net]
Pretty quick solution to your question there.