required() in php

index.php :
<?php

@require 'required-page.php';


echo '<br>';
echo 'home page';


?>
output :

database connected
home page
===========================================================
 required-page.php :
<?php

mysql_connect('localhost','root','') or die('not connected');
echo '<center>database connected</center>';

?>
==========================================================
sub-page.php :

<?php

@require 'required-page.php';
echo 'sub page';

?>

output :

database connectedsub page
==========================================================
note :

1) ' @ ' use for don't  display errors related to php

2) if there is no  ' include-page.php ' page then nothing is display in included pages like ' index.php  ' , 'sub-page.php '

3) here ' index.php ' , ' sub-page.php ' pages  are run