Why it doesn`t works?

i did not understand clear what do you want to draw, but here is a part from program i've wrote once - it is a masm example, but i think you will need just refer to it - may this will help. it was just drawing with mouse when or left, either right button pressed (when my daughter was too small, she pressed mostly right button with all fingers Smile

)

Code:

        .elseif uMsg==WM_RBUTTONDOWN
                jmp lbd
        .ELSEIF uMsg==WM_LBUTTONDOWN
lbd:    mov eax,lParam
                and eax,0ffffh
                mov lastpoint.x,eax
                mov eax,lParam
                shr eax,16
                mov lastpoint.y,eax
                mov dopaint,TRUE
        .elseif uMsg==WM_MOUSEMOVE
                .if dopaint
                        mov eax,lParam
                        and eax,0ffffh
                        mov hitpoint.x,eax
                        mov eax,lParam
                        shr eax,16
                        mov hitpoint.y,eax
                        invoke GetDC,hWnd
                        mov    hdc,eax
                        invoke MoveToEx,hdc,lastpoint.x,lastpoint.y,NULL
                        invoke LineTo,hdc,hitpoint.x,hitpoint.y
                        mov eax,hitpoint.x
                        mov lastpoint.x,eax
                        mov eax,hitpoint.y
                        mov lastpoint.y,eax
                        invoke ReleaseDC,hWnd,hdc
                .endif
        .elseif uMsg==WM_RBUTTONUP
                jmp lbu
        .elseif uMsg==WM_LBUTTONUP
lbu:    mov eax,lParam
                and eax,0ffffh
                mov hitpoint.x,eax
                mov eax,lParam
                shr eax,16
                mov hitpoint.y,eax
                invoke GetDC,hWnd
                mov    hdc,eax
                invoke MoveToEx,hdc,lastpoint.x,lastpoint.y,NULL
                invoke LineTo,hdc,hitpoint.x,hitpoint.y
                invoke ReleaseDC,hWnd,hdc
                mov dopaint,FALSE

regards!