Resizing child windows using phobos

[Alex]

So i have been trying to send WM_SIZE messages to my child 
windows in my application window proc. I am sending theese 
messages when the application window is resized. But it will not 
work. They keep the same child window size as they have from when 
they were initialized.

Is there any other methods that i can use that are already 
included in the phobos libraries?

Thanks for any help.