How to Comment code

[Nirjonadda]

Please let me know that How comment the below code?

/* DATABASE */

if(!file_exists(dirname(dirname(__FILE__)).DIRECTORY_SEPARATOR.'library'.DIRECTORY_SEPARATOR.'config.php')) {
    echo "Please check if imageiconis installed in the correct directory.<br /> The 'imageicon' folder should be placed at <XENFORO_HOME_DIRECTORY>/imageicon";
    exit;
}
include(dirname(dirname(__FILE__)).DIRECTORY_SEPARATOR.'library'.DIRECTORY_SEPARATOR.'config.php'); //Xenforo DB configuration file