//Check to make sure the data has been entered before saving
function SaveClient(&$dbconnection)
{
    //If there are empty fields: a message is displayed
    if (empty($_POST['title']) || empty($_POST['firstname']) || empty($_POST['surname']) || empty($_POST['email']) || empty($_POST['addressline1']) || empty($_POST['town']) || empty($_POST['county']) || empty($_POST['postcode']) || empty($_POST['homephone']) || empty($_POST['dateofbirth']) || empty($_POST['username']))
        return "<p>You must fill in all fields!<br />".AddClientForm(); //Display the form to add a client
        
    $title = EscapeData($_POST['title'], $dbconnection);
    $firstname = EscapeData($_POST['firstname'], $dbconnection);
    $surname = EscapeData($_POST['surname'], $dbconnection);
    $email = EscapeData($_POST['email'], $dbconnection);
    $addressline1 = EscapeData($_POST['addressline1'], $dbconnection);
    $town = EscapeData($_POST['town'], $dbconnection);
    $county = EscapeData($_POST['county'], $dbconnection);
    $postcode = EscapeData($_POST['postcode'], $dbconnection);
    $homephone = EscapeData($_POST['homephone'], $dbconnection);
    $dateofbirth = EscapeData($_POST['dateofbirth'], $dbconnection);
    $username = EscapeData($_POST['username'], $dbconnection);
    
    //Query to show if the user name already exists
    $query = "SELECT username FROM Customer WHERE (username = '$username')";
    $result = @mysql_query($query); //Run the query.
    if ($result) //If it ran ok, display the records.
    {
        if (mysql_num_rows($result) > 0) //The client name already exists
            return "<p>Unfortunately that user name already exists, please choose another</p><br />".AddClientForm(); //Display the form to register the client
        mysql_free_result($result); //Free up the resources.
    }
    //Checks that there are no invalid characters in the title
    if (!preg_match("/^[A-Za-z' -]{2,50}$/", stripslashes(trim($title))))
    return "<p>Please, enter a valid title!</p><br />".AddClientForm(); //Display the form to add a new client
    
    //Client forename checking
    if (!preg_match("/^[^';=]{5,255}$/", $firstname)) //Security (for avoiding malicious entries)
    return "<p>Please enter a valid forename!</p><br />".AddClientForm(); //Display the form to add a new client
    
    //The passwords are checked to see if they are the same
    if (strcmp($_POST['password1'], $_POST['password2']) != 0)
    return "<p>Your password did not match the confirmed password, please try again</p><br />".AddClientForm(); //Display the form to add a client

    //Checks that there are no invalid characters in the password
    $password = EscapeData($_POST['password1'], $dbconnection);
    if (!preg_match("/^\w{5,16}$/", $password))
    return "<p>Please, enter a valid password!</p><br />".AddClientForm(); //Display the form to add a client
    
    else {
        $query = "INSERT INTO Customer (title, firstname, surname, email, addressline1, addressline2, town, county, postcode, homephone, dateofbirth, workphone, mobile, username) " .
                "VALUES ('$title', '$firstname', '$surname', '$email', '$addressline1', '$addressline2', '$town', '$county', '$postcode', '$homephone','$dateofbirth', '$workphone', '$mobile', '$username', PASSWORD('$password'))";
        @mysql_query($query);
        return "<p>The client has been saved</p>".ClientsForm(); //Display the form with all clients
        echo $firstname;
        }
}