Heatmap - How to add server-side code from within the browser

Question

We use a heatmap at work (it is secure so I can't post it here and I certainly cannot give the url). Now the heatmap is a sigle image, but it is clickable on different segments - There are different icons on the map and each of them pops up a different window(So it is not just a single click event for the whole image)...

Now this map is generated by a program called Whatsup Gold, and it is definitely not Flash...

The map constantly monitors line connection activity - When an internet line goes down, the green icon turns red. The map is refreshed every few minutes...

What I want to know: Is there a way, either using a browser plugin, or Javascript, or any other method to notify me that the status of the map has changed(any change on the map) without having to open the browser window everytime?

Here is the part of the markup of the map...(the whole map)

<a href="mappickhost.asp?map=WhatsUpTL.wup">
   <img border="0" src="WUG1.jpg" ismap="">
</a>

Update:

Request and Response headers(As retrieved from Firebugs Network tab)

Request:

Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

Accept-Encoding:    gzip, deflate

Accept-Language:    en-US,en;q=0.5

Authorization:  Basic dGxpbms6dGxpbms=

Cache-Control:  max-age=0

Connection: keep-alive

Host:           ***************

Response

Cache-Control   no-cache

Content-Type    image/jpeg

Date    Fri, 17 May 2013 07:06:30 GMT

Expires Mon, 17 Jul 1980 20:00:00 GMT

Pragma  no-cache

Server  WhatsUp_Gold/8.0

Answer 1

I have added a screenshot of firebug console in firefox (press F12 to open it). I executed a xmlhttprequest (line at the bottom) and you can see (the black line) that it connected to stackoverflow. Firebug shows xhr connections in the console by default but you can select what you want to see by clicking the little arrow button to the right of the word "Console" in the tab that activates the console.

Even having the console open with StackOverflow shows that the site connects every so often to update question status and comments.

If nothing shows up there than it might show in the Net tab. It has to make a connection to somewhere to see if network is still up. If it connects to a service than xhr is likely if it just tries to download a textfile sometmes or sets the src of an image than it'll show up only in the net tab every time it checks.