Page redirection based on an event trigger

[justaguy]

Hi,

I wonder if there's a way to cause a page redirection based on an
event of the current page.

What I'd like to happen is:
If the user does not click on the [Download] button I'll redirect him/
her to a tips page, namely,
the best-note-taking-tips-from-10-colleges.html file
in the review directory

My attempt is:
include a hidden field named 'downloadChk' in the form of 'f'
with default value of 0
if the download button is clicked, change that field's value to 1
(business role: in that case no need for redirection),
then with the event of onbeforeunload at BODY element to determine the
page redirection or not...

Status:
Not working. That is, when the condition is true page redirection did
not occur.

Here's the page,
http://www.knowledgenotebook.com/download_dev.html

What am I doing wrong? How to fix it?

Many thanks.