Retrieve CGI Variables From Javascript

Here's the situation. I have a static html page which we want to update
to include some dynamic content. I want a counter that keeps track of
the number of times anyone presses the "add" button, and display that
number. So, that page would look something like:

Number of calls today: 5
Add | Reset

The "5" would increment with every click of the "Add" link. The "Reset"
link would reset the counter to 0.

I have a Perl script that does all of the accounting stuff (opens a file
that contains the number, increments it, resets it, etc). What I don't
know how to do is to get the data from the CGI script to the web page.
I'm imagining that you can use Javascript, but I can't figure it out.
My CGI script can accept three options (add, view, reset). So it you
call it like so [myscript.cgi?action=add], it increments the counter by one.

So, in a nutshell, this is what I want:

1) the web page to display the # of calls upon load.
2) When a user presses the "Add" link, it invokes the CGI script to
handle the accounting stuff, then refresh the page with the new number
of calls.
3) When a user presses the "Reset" link, it resets the counter to 0.