System.Windows.Forms.MessageBoxManager.MessageBoxHookProc C# (CSharp) Method

        private static IntPtr MessageBoxHookProc(int nCode, IntPtr wParam, IntPtr lParam)
        {
            if (nCode < 0)
                return CallNextHookEx(hHook, nCode, wParam, lParam);

            CWPRETSTRUCT msg = (CWPRETSTRUCT)Marshal.PtrToStructure(lParam, typeof(CWPRETSTRUCT));
            IntPtr hook = hHook;

            if (msg.message == WM_INITDIALOG)
            {
                int nLength = GetWindowTextLength(msg.hwnd);
                StringBuilder className = new StringBuilder(10);
                GetClassName(msg.hwnd, className, className.Capacity);
                if (className.ToString() == "#32770")
                {
                    nButton = 0;
                    EnumChildWindows(msg.hwnd, enumProc, IntPtr.Zero);
                    if (nButton == 1)
                    {
                        IntPtr hButton = GetDlgItem(msg.hwnd, MBCancel);
                        if (hButton != IntPtr.Zero)
                            SetWindowText(hButton, OK);
                    }
                }
            }

            return CallNextHookEx(hook, nCode, wParam, lParam);
        }