C [C++] Win32 API - Modifying the text of a child window

Code
#define _WIN32_WINNT 0x0500



#include <windows.h>

#include <string>



int main() {



    // The console's window handle (used for MessageBox dialogs)

    HWND hwnd = GetConsoleWindow();



    // The window title we're searching for (the Notepad)

    std::string windowTitle("HackForums.txt - Notepad");



    std::string textToSend("HackForums example\r\nSendMessage() successfully edited the text!\r\n- Irritiable@HackForums");



    // The window handle of the parent handle to the Notepad

    HWND hwndParent = FindWindow(nullptr, windowTitle.c_str());



    // Error is thrown if the value returned is NULL

    if (hwndParent == nullptr) {

        std::string errorBuffer("The parent window's handle returned: NULL");

        MessageBox(hwnd, errorBuffer.c_str(), "HackForums - ERROR", MB_ICONERROR);

        return -1;

    }



    // The window handle of the child handle to the Notepad's internal edit box window

    HWND childHwnd = FindWindowEx(hwndParent, nullptr, "Edit", nullptr);



    // Error is thrown if the value returned is NULL

    if (childHwnd == nullptr) {

        std::string errorBuffer("The child window's handle returned: NULL");

        MessageBox(hwnd, errorBuffer.c_str(), "HackForums - ERROR", MB_ICONERROR);

        return -1;

    }



    // SendMessage dispatches the official message (WM_SETTEXT) to the child window handle with the character data

    if (SendMessage(childHwnd, WM_SETTEXT, 0, reinterpret_cast<LPARAM>(textToSend.c_str())) == false) {

        std::string errorBuffer("WM_SETTEXT returned FALSE (data not sent)");

        MessageBox(hwnd, errorBuffer.c_str(), "HackForums - ERROR", MB_ICONERROR);

        return -1;

    }



    return 0;

}