使用php中的函数创建数据库连接？

So really I just want to make stuff easier to read and just create a function where I can call upon the database connection, the below is what i've tried to do to do far.

So far, it doesn't work, it doesn't bring any message at all so presumably it isn't going into the try.

functions.php

function getDBConnection()
{
    try
    {
        $db = new PDO('mysql:host=localhost;dbname=name;charset=utf8', 'username', 'password');
        $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); //Set error mode
    }
    catch(PDOException $e)
    {
        echo 'An error occured talking to the DB';
    }
    return $db;
}

and then do

submittest.php

require('functions.php');
getDBConnection(); //return $db


$username = 'donkey';
$password = 'donkey';
$email = 'donkey';
$county = 'donkey';

    try
    {
        //Prepare and execute an insert into DB
        $st = $db->prepare("INSERT INTO users(login,pass,email,county) VALUES(:username,:password,:email,:county)");
        $st->execute(array(':username' => $username, ':password' => $password, ':email' => $email, ':county' => $county));
        echo 'Success';
    }
    catch (PDOException $e)
    {
        echo 'An error occurred talking to the DB';
    }
?>

$db = getDBConnection(); //return $db