Must I implement resizing myself?

[Richard Andrew x64]

I have child windows that I want to be resizable, but I don't want them to have title bars. I've experimented with the various styles and I can't get the windows to have sizing borders without also having the title bar. Does this mean that I must implement my own home-brewed sizing border for the client windows?

The difficult we do right away... ...the impossible takes slightly longer.