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#include "windows.h"

HWND hTargetWindow;  
HWND hWindow;  

LRESULT CALLBACK WindowProc(
  HWND hwnd,
  UINT uMsg,
  WPARAM wParam,
  LPARAM lParam
)
{
    hWindow = GetFocus();
    return true;
}

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    LPWSTR lpCmdLine, int nCmdShow) {
   
    LONG oldWNDPRC;
    TCHAR szText[620];

    hTargetWindow = GetForegroundWindow();

    if (IsWindowVisible(hTargetWindow)==0)
    {
        while( (hTargetWindow=GetWindow(hTargetWindow,GW_HWNDNEXT))!=NULL)
        {
            if (IsWindowVisible(hTargetWindow)!=0)
            break;
        }
    }

    oldWNDPRC = GetWindowLong(hTargetWindow, GWL_WNDPROC);
    SetWindowLong(hTargetWindow, GWL_WNDPROC, (LONG)&WindowProc);
    SendMessage(hTargetWindow,WM_NULL, 0, 0);
    SetWindowLong(hTargetWindow, GWL_WNDPROC, oldWNDPRC);
    GetWindowText(hWindow,szText,620);

    return 0;
}