Problems with IE8 or Windows 7

[mcolton]

My website, www.LOTAtennis.com is having a problem. If you mouseover or click "Headlines" and select "Info Changes", you get to a page asking for first and last names. If you don't enter names and click submit, you are supposed to get a popup box saying names are required fields. The same with the next page, the "Information Update Form". If you don't fill it out and click submit, you should get a popup box telling you all the fields you didn't enter; not a new white page only telling you about an incorrect email address.

This works correctly on a laptop with Vista and IE7 but does not work with my pc with Windows 7 and IE8.

HELP. Can anyone point me in the right direction as to how to fix this.
If I am in the wrong place, please let me know. Thanks for any help.

[mcolton]

I put a meta tag in my code to emulate ie7 and the code works so IE8 is the problem.
Is there someone who can look at my code and let me know what IE8 doesn't like.
Is there someplace that tells me what changes IE8 made to html coding.