#include<bits/stdc++.h>
#include<windows.h>
#include<conio.h>
using namespace std;
int main()
{
	if(WM_CLOSE)
	{
    	if(MessageBox(hwnd, L"Really quit?", L"My application", MB_OKCANCEL) == IDOK)
	    {
	        DestroyWindow(hwnd);
	    }
	}
    return 0;
}

emm这代码CE了

'hwnd' was not declared in this scope