Widen the central column, narrow the two on either side?

[eyescombe]

I'm pretty new to css. How can I achieve this?

Many thanks.

[eyescombe]

Ok, I figured it out. The problem now is the dividing lines in the
narrow sidebars. In IE they are lined up perfectly, but in firefox
they are jutting out in an ugly way. How can I shorten them? I'd
rather have then come up short in IE than the alternative.

thanks