Since, as was pointed out to you ( or someone like you) in another node, you'd need to have your script interact with the Netscape application, this is hard to make work on Unix.

Therefore, your script would have to be a proxy, sitting between your Netscape and the Web, so it could see all the pages you retrieve and check them. Of course, if you judt want to kill the popups (and don't want to use Mozilla for some reason), you could use junkbuster - as this is a proxy that sits between your browser and the web watching what goes by and acting on it.

Otherwise, tell your professor he's asking for the impossible (or near impossible).

Update: You could run the code previously suggested in a loop that waited for a URL to be given on STDIN, then checked the page and repeated. Then you could copy and paste the URLs from the Location field in Netscape to the treminal where your script is running. Other than that, good luck.