Графический интерфейс для приложения c++

#include <windows.h>
 
 
MSG             msg;
HWND            hwnd, edit1, edit2, button;
char            buff[1024];
bool            quit = false;
 
 
LRESULT CALLBACK MsgProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message) {
        case WM_QUIT:       PostQuitMessage(0); break;
        case WM_CLOSE:      PostQuitMessage(0); break;
        case WM_DESTROY:    PostQuitMessage(0); break;
        case WM_COMMAND:
            if (LOWORD(wParam)==777) {
                GetWindowText(edit1, buff, 1024);
                /* ЗДЕСЬ ВАША ФУНКЦИЯ ПРЕОБРАЗОВАНИЯ */
                SetWindowText(edit2, buff);
            }
    }
    return DefWindowProc (hWnd, message, wParam, lParam);
}
 
 
int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInstance, LPSTR lpszArgument, int nCmdShow)
{
    WNDCLASSEX wincl;
    wincl.hInstance     = hInst;
    wincl.lpszClassName = "app";
    wincl.lpfnWndProc   = MsgProc;
    wincl.style         = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
    wincl.cbSize        = sizeof(WNDCLASSEX);
    wincl.hIcon         = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm       = NULL;
    wincl.hCursor       = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName  = NULL;
    wincl.cbClsExtra    = 0;
    wincl.cbWndExtra    = 0;
    wincl.hbrBackground = (HBRUSH)(1);
    RegisterClassEx(&wincl);
 
    hwnd = CreateWindowEx(WS_EX_APPWINDOW, "app", "...", WS_OVERLAPPEDWINDOW, 50, 50, 400, 400, HWND_DESKTOP, NULL, hInst, NULL);
    ShowWindow(hwnd, nCmdShow);
 
    edit1   = CreateWindowEx(WS_EX_CLIENTEDGE, TEXT("Edit"), TEXT(" "), WS_CHILD|WS_VISIBLE|WS_BORDER, 100, 20, 140, 25, hwnd, NULL, NULL, NULL);
    edit2   = CreateWindowEx(WS_EX_CLIENTEDGE, TEXT("Edit"), TEXT(" "), WS_CHILD|WS_VISIBLE|WS_BORDER, 100, 50, 140, 25, hwnd, NULL, NULL, NULL);
    button  = CreateWindow(TEXT("button"), TEXT("Кнопка"), WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON, 10, 10, 80, 30, hwnd, (HMENU)777, hInst, NULL);
 
    while ( !quit ) {
        if ( PeekMessage(&msg, NULL, 0, 0, PM_REMOVE) ) {
            if ( msg.message == WM_QUIT )
                quit = true;
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
        else {
            Sleep(1);
        }
    }
    return 0;
}