Connection

<?php
//start a session
session_start();
// db properties:
$dbhost = 'localhost';
$dbuser = 'root'; 
$dbpass = 'pass_word';    
$dbname = 'academia';
?>

2. Check the connection

<?php
//in the case of failure to connect to the database:
$conn = mysql_connect ($dbhost, $dbuser, $dbpass) or die ("Could not 
connect to the database: " . mysql_error());

//in the case of failure toselect a  database:
mysql_select_db ($dbname) or die ("I cannot select the 
database '$dbname' because: " . mysql_error());
?>

3. Close the connection

<?php
mysql_close($conn);
?>

4. Creating a library

Set the above code as config.php file in 
the library directory: library/config.php 
This file will be called when needed.

library/config.php

<?php
//start a session
session_start();
// db properties:
$dbhost = 'localhost';
$dbuser = 'root'; 
$dbpass = 'pass_word';    
$dbname = 'academia';
?>

//in the case of failure to connect to the database:
$conn = mysql_connect ($dbhost, $dbuser, $dbpass) 
or die ("Could not connect to the 
database: " . mysql_error());

//in the case of failure toselect a  database:
mysql_select_db ($dbname) or die ("I cannot select 
the database '$dbname' because: " . mysql_error());