It sounds very similar the the Anti Virus 2008 & 2009 - we had posts about it too.
gives a pop up saying it will install a good antivirus program - but it is a virus instead!

yep, do not click anywhere on those.
close /Exit your browser if you can

Or
use Ctrl/Alt/Del to open task manager and select browser {iexplore, or firefox, ect} then use close/end process to shut it down that way

Or
if you aren't comfortable using that - shut down computer and reboot, but don't go back to that website or page you were on before.

here's some of the other threads -
http://neurotalk.psychcentral.com/thread59061.html
http://neurotalk.psychcentral.com/thread64192.html