How can I get the value of a form input whose name is in a Javascript variable?

[email protected] ("Neelay") 7 Jun 2006 17:29:05 -0700
Newsgroups perl.javascript
Organization http://groups.google.com
Message-ID <[email protected]>
Hi all,
I have a Javascript variable, containing the name of an input-
input_name = "document.myform.ip"
How can I get the value of the input "ip" using the variable input_name
in Javascript?
Any help will be highly appreciated.

Thanks,
Neelay.