This site is actually for centering the pop-up window, but look futher down in PINK there is code for setting the dimensions.
http://www.dynamicdrive.com/dynamici...autocenter.htm

Be aware that some people have pop up blockers disallowed.
Also some people really really hate it when you resize their windows. Just words of caution for you.
Also, I do not believe this will delete the toolbars... not sure.