My demo.php code is as below. The error that I got was You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''FullName', 'Email', 'Postcode', 'DateofBirth', 'Gender') VALUES ('David Beckham', ' at line 1
  <?php
define('DB_NAME', 'testdb');
define('DB_USER', 'root');
define('DB_PASSWORD', '');
define('DB_HOST', 'localhost');
//logon
$link = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);
if(!$link){
     die('Could not connect: '. msql_error());
} 
$db_selected = mysql_select_db(DB_NAME, $link);
    if(!$db_selected){
       die('Cant use' . DB_NAME . ':' . mysql_error());
    }
    $value = $_POST['FullName'];
    $value2 = $_POST['Email'];
    $value3 = $_POST['Postcode'];
    $value4 = $_POST['DateofBirth'];
    $value5 = $_POST['Gender'];
//insert into table.
$sql = "INSERT INTO demo ('FullName', 'Email', 'Postcode', 'DateofBirth', 'Gender') VALUES ('$value', '$value2', '$value3', '$value4', '$value5')";
if(mysql_query($sql)){
   echo "Thank you for signing up";
}else{
   die('Error:'. mysql_error());
}
mysql_close();
?>
 
     
    