open a new window, but it's pop up window size

I'm wanting to have my users open up a new window just big enough for them to read some info. On my site I'm going to place a link with "what's this" as the anchor text or just "?", where they can click on it and read the content in the smaller window. From my understanding this is done with Java script. How do you do it? I don't use Java script at all.

Thanks

 

You might find this useful:

http://www.dynamicdrive.com/dynamicindex8/popwin.htm

 

Wow, that's a sweet tool. I tried it and it works.

Thanks!

 

Nearly 5years later, and still helpful. Thanks!