LNK2019 ругается на HWND

#include <Windows.h>
 
#define WIDTH 640
#define HEIGHT 480
 
LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
int CALLBACK WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    WNDCLASSEX iWindow;
    MSG uMsg;
    HWND hWnd; //эта строка, как я выяснил
    memset(&iWindow, 0, sizeof(WNDCLASSEXW));
    iWindow.cbClsExtra = sizeof(WNDCLASSEX);
    iWindow.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    iWindow.hCursor = LoadCursor(NULL, IDC_ARROW);
    iWindow.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    iWindow.hInstance = hInstance;
    iWindow.lpfnWndProc = WindowProc;
    iWindow.lpszClassName = "Simple Window";
    RegisterClassEx(&iWindow);
    hWnd = CreateWindow(iWindow.lpszClassName, "test cpp", WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_THICKFRAME | WS_MINIMIZEBOX | WS_MAXIMIZEBOX,
        (GetSystemMetrics(SM_CXSCREEN)-WIDTH)/2, (GetSystemMetrics(SM_CYSCREEN)-HEIGHT)/2, WIDTH, HEIGHT, NULL,NULL,NULL,NULL);
    ShowWindow(hWnd, nCmdShow);
}

LRESULT CALLBACK WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    return DefWindowProc(hWnd, uMsg, wParam, lParam);
}

...
            ShowWindow (hWnd, nCmdShow);
        MSG msg;
        while (GetMessage(&msg,NULL,0,0) > 0)
        {
            TranslateMessage (&msg);
            DispatchMessage (&msg);
        }
        return msg.wParam;