I have a pure HTML website with some mini Javascripts embedded.

One of the Javascripts in particular does the following:

1. Capture a "region" keyword entered by a user (e.g. "PST")
2. Based on the KW, display one line of text that is different based
on the KW entered in 1. (e.g. 'You are redirected to the West Coast
Page')
3. Redirect to another HTML page based on on the KW entered in 1. (e.g. west.html)

Everything is working perfectly and I tested everything with different
browsers.  In my Apache log, a typical succesful interraction would
be:
GET homepage.html 200
GET west.html 200 (+ referrer: homepage.html)

However, I noticed that many lines also come with the following
A)
GET homepage.html?input=west 200
<and no GET to the west.html page.>

or B)

GET homepage.html?input=west 200
GET west.html 200

My question is why and/or under which circumstance does Apache record
the ?input= and what does that mean?

I would understand this issue if the data of the form were actually
sent to the server for processing but it is not the case here. It is a
pure client script, with a request for another page coming from the
client app.

Is it a bug? or is A) only a bug? Is it specific to a particular type
of browser or other parameter? I tried to debug this by analyzing the
log with all other information provided but I could not find anything
consistent.

I definitely do not understand why the input value is passed to the
server. The server should not see this value, only a redirection
request to a new page. This enables me to make a quick decision lookup
without creating a lot of server code. It has also a perfect
scalability.

I Set a price of $5.00. Can pay more if the solution is complicated.
Thanks, Guys. I cannot post the full code for confidentiality reasons.
But it is very basic: get the string, clean it, add .html, then
redirect.