Browser detection in Javascript

I have a need for a good, but not precise, browser sniffing script for purposes of web visitor logging. I have hacked together such a script. I would be very grateful if my visitors would tell me if the blue box is telling them the truth (javascript needed):

It’s been confirmed to work on:

• Mac : Safari 2.0.4 (419.3)
• Mac : Firefox 1.5, 2.0, 3.0
• Mac : Opera 9.02
• Mac : MSIE 5
• Windows : MSIE 5.01, MSIE 6, MSIE 7 rc1, MSIE 7
• Windows : Firefox 1.5, 2.0, 3.0