[WinAPI, C++] Edytowanie zawatrości TextBox-ów

void AddWindowText( HWND hWnd, char * text )
{
    int length = GetWindowTextLength( hWnd );
    LPSTR buffer =( LPSTR ) GlobalAlloc( GPTR, length + 1 );
    GetWindowText( hWnd, buffer, length + 1 );
    int size = strlen( text );
    char * write = new char[ length + size + 1 ];
    strcpy( write, buffer );
    strcat( write, text );
    SetWindowText( hWnd, write );
    GlobalFree( buffer );
    delete[] write;
}