Variable declaration:-
$firstname="";
$surname ="";
$id ="";
$faculty_of_study= "";
$enrolled_course ="";
$gender ="";
$password= "";
$telephone_no="";
$email_address="";
$sql="";
$firstname = addslashes($_POST["firstname"]);
$surname = addslashes($_POST["surname"]);
$id = addslashes($_POST["id"]);
$faculty_of_study = addslashes($_POST["faculty_of_study"]);
$enrolled_course = addslashes($_POST["enrolled_course"]);
$gender = addslashes($_POST["gender"]);
$password = addslashes($_POST["password"]);
$telephone_no = addslashes($_POST["telephone_no"]);
$email_address = addslashes($_POST["email_address"]);
$sql = "INSERT INTO people (firstname, surname, id,faculty_of_study, enrolled_course, gender, password, telephone_no, email_address); VALUES ("$firstname", "$surname", "$id", "$faculty_of_study", "$enrolled_course", "$gender","$password", "$telephone_no", "$email_address")";
syntax error unexpected '$firstname' (T_VARIABLE) on line 21