Personally, I rarely use ID's. Older versions of Netscape handle classes, but not ID's. I see no reason why #content can't be .content. The only exception for me is if I'm using JavaScript and don't want to do a getElementByClassName function.

well, IDs can only be used once on a page and classes can be used multiple times. Lets say you have 3 text boxes, you can put a class in them to format them all the same and in each put a unique id in case you need to get the specific value from one of them.

Thx mate fore sharing the info