Window doesn't appear - c++

Question

I have written a small program to create a window. I have made this program before, but now I'm trying to recollect all the things for myself.
When I was done writing the program, the window won't appear, and when I compare my code to the book I'm learning from, its the same. What am I missing/doing wrong?
#include <windows.h>
#include <WindowsX.h>
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, INT nCmdShow)
{
HWND hWnd;
// information for the window class
WNDCLASSEX wc;
ZeroMemory(&wc, sizeof(WNDCLASSEX));
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = WindowProc;
wc.hInstance = hInstance;
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)COLOR_WINDOW;
wc.lpszClassName = "WindowClass1";
RegisterClassEx(&wc);
// Create Window
hWnd = CreateWindowEx( NULL,
"WindowClass",
"My Program",
WS_OVERLAPPEDWINDOW,
100,
100,
600,
480,
NULL,
NULL,
hInstance,
NULL);
ShowWindow(hWnd, SW_SHOWDEFAULT);
MSG msg;
while(GetMessage(&msg, NULL, 0,0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch(message)
{
case WM_DESTROY:
{
PostQuitMessage(0);
return 0;
} break;
}
return DefWindowProc(hWnd, message, wParam, lParam);
}

Answer 1

Compare class names:
wc.lpszClassName = "WindowClass1";
hWnd = CreateWindowEx( NULL, "WindowClass", ...
The best way to find such errors is to check return code of every API.