ominous message on screen, safari no longer

I got the following message on the while in safari:

from http://i0s-livesupport.biz

****WARNING!! OS Crash Report****

Due to a third party application

your operating system is crashed.

Contact Support for Immediate Fix

1-866-537-7060 (Toll Free)

-----

I have not called the number above.

I have restarted the system.

Now when I run safari, the message is displayed, and safari is unusable.

I'm composing this post using another browser.

Two issues:

1. how can I fix safari?

2. failing that, how can I get another browser to open when I click on a link?

Thanks.