A simple error handler that makes errors far more visible:

    //
    // Set the error handler to one that prints out more
    // visible errors
    //
    set_error_handler(function ($errno, $errstr)
    {
        $str = '<div style="margin: 20px; background-color: #fdd; border: 3px solid red; padding: 10px; border-radius: 15px; line-height: 25px"><b>Error: </b>%s (error level: %s)</div>';
        
        printf($str, $errstr, $errno);
    });