Pop Unders
 

a web site is generating pop unders every time I click on it (local newspaper)

I use Firefox and have them in the set of not allowed for pup ups.

Do I need an add on? If so, what's the best one?

AdBlock plus should get most of them

+1 adblock plus is the best. It'll probably do it.

If it doesn't, then noscript, but it requires more work.

The first two extensions on this page.
https://addons.mozilla.org/en-US/firefox/extensions/

Adblock Plus will catch almost everything. If there's anything that it doesn't catch, you can right click and then "add" that item to stuff that it'll catch next time.

noscript will pretty much blanket deny everything everywhere all of the time, and then you add stuff back in. That's why it's more administratively intensive. You have to allow stuff on every page that you go to.

thx - turns out I had Ad Block+ on the XP machine & forgot about it. Will install on the Win 7 box.