Browser window alert

I need to know what I am looking for is even possible. We have a C#/javascript web app that alerts our staff of a new customer waiting in our lobby. When a new customer arrives the front desk puts their name into the web app. All available representatives have the web app open at their desks. The web app is polling for customers, when it detects one is waiting it pops a new browser window up on to the screen to alert the representative. The issue we are having is the representatives are minimizing the alert window rather than closing it. When you minimize the alert window the web app won't trigger another one. We need to figure out a way to bring the alert back to focus on the screen or close it and open another one. I've attached a screenshot of the browser alert window that the representatives see.

Is there a way to take a minimized browser window and force it to come back into focus on the screen after 30 seconds?