How to remove the underline in text links?

I got actually two questions about text links.

  1. How can i remove the underline in text links? For example if i want the under line just to appear when i hover the text? Is that possible?

  2. I am using one of the templates and some text are on top of a grey sqaue. I want to link the text inside the grey square but its seems impossible. In that case i need to create either a link block or linked text. If i do that the square disappears.

Thanks in advance,

/Tobas