2 tips on html
Centering a block without using HTML <center> tag
To align a block to the center of the containing block you can set both 'margin-left' and 'margin-right' properties of the block to 'auto'.
The width of the internal block should of course be smaller than the parent's.
Adding tooltips to links
You can add mouse-over tooltip to the links on your web page by adding a 'title' attribute to the tag. For example:
<a href="www.cnn.com" title="click here">CNN</a>