help plz

Are there any javascripts out there that perform this kind of action? Say, I have enty:

Date: December 25, 2005
Title: Hey
Content: What's up?

What I want to perform is that there is a link under that content "comment" and when the users click on that link, it will take them to a form that they can write comment, my problem is that on the form, I want the Title input has the text already, in other words, whatever the title of that entry is, it will go automatically to the Title input box on the comment form. Is this possible to achieve? I could not find any resources about this.

document.getElementById('txtboxname').value="Whatever you want";

But that only allows me to set the Title for only one entry, I want it to be set automatically according to the Title, can that be done by using Javascript and Perl together?