About Scroll bar, please help

I am writing a notepad and the picture is my work
my problem is: when I resize the window, the positions of scrollbars don't move.

How do I solve this problem ?

and when the window created, the positions of scrollbars are not align to right and bottom.......

If you create your window with the WS_VSCROLL|WS_HSCROLL styles, windows will ensure the scrollbars are positioned correctly when you resize the window. If you must use scrollbars controls then handle the WM_SIZE message for the parent window; use MoveWindow, or SetWindowPos if you prefer, to reposition them.

Thanks !
I do it by SetWindowPos
Really thanks!