win32 insert into rich edit

void insertMessage(HWND hWnd, char *message) {

  // get handle
  HWND hEdit1 = GetDlgItem(hWnd, IDC_MAIN_EDIT);

  // get string length
  int strLen = GetWindowTextLength(hEdit1);

  // allocate memory
  char *buffer = new char[strLen+strlen(message)+11];

  // get text
  GetWindowText(hEdit1, buffer, strLen + 1);


  // update window text
  SetWindowText(hEdit1, buffer);

  // auto scroll
  SendMessage(hEdit1, WM_VSCROLL, (WPARAM)SB_BOTTOM, MAKELPARAM(FALSE, 0));

  // free allocated memory
  delete [] buffer;

}