insertcode File for Insert data in PHP

 <?php

include("mysqli_conn.php");

if (isset($_POST["insertdata"])) {

    $fname = $_POST["fname"];

    $lname = $_POST["lname"];

    $course = $_POST["course"];

    $contact = $_POST["contact"];

    $sql = "INSERT INTO student(`fname`, `lname`, `course`, `contact`) VALUES('$fname','$lname','$course','$contact')";

    if ($conn->query($sql) == TRUE) {

        echo "<script>alert('Data Saved');</script>";

        header("Location: index.php");

    } else {

        echo "<script>alert('Data Not Saved');</script>";

    }

}