Resizing A Skinned Window

Is there a way where I can retreive the current size of a HTML document window? This is how it works. When i use the Microsoft Internet Control and i open a new window is there a way to get the current HTML window size? This way when a new window pops up my application resizes its self to the current size of the document. Also can i have this code where when i drag a image it can resize the form? So when i drag this image it can resize itself.

Can this be done? Any help will be useful.