CSS Issues in IE

[mowen10]

Hi, i am learning how to use CSS and I have come across issues with how pages are displayed in different browsers. A friend is designing a website and I asked him if i can learn some css, so he gave me a link for a website that he is working on that displays differently in IE but appears ok in browsers such as opera and firefox.

I have learnt how to apply divs and different styles, but not sure how to resolve this. The URL is : mymedsdirect.co.uk

Any help or advice would be appreciated. Also tips on how to distinguish issues with stylesheet would be really appreciated.

Thanks in advance.

[mowen10]

Ok my friend has managed to setup his website making amendments to help fix issues with IE and he has asked me to work out why the following 2 links show up differently.

http://www.mymedsdirect.co.uk/index.php

http://www.mediadezines.co.uk/oscommerce-2.3.1-edited/catalog/index.php

They both have the same stylesheet but the first link shows up all over the place. Any ideas any1?