<h2>Reserve Asset</h2>

    <form action="Student_Asset.php" method="post" enctype="multipart/form-data">
        <div class="form-group">
            <label for="asset_id">Asset ID:</label>
            <input type="text" id="asset_id" name="asset_id" value="<?php echo $_GET['id']; ?>">
        </div>

        <div class="form-group">
            <label for="student_id">Student ID:</label>
            <input type="text" id="student_id" name="student_id" value="<?php echo $_SESSION['student_Id']; ?>">
        </div>

        <div class="form-group">
            <label for="reservation_date">Reservation Start Date:</label>
            <input style="background-color: blue;" type="date" id="start_date" name="start_date" >
        </div>

        <div class="form-group">
            <label for="duration">Reservation End Date:</label>
            <input style="background-color: green;" type="date" id="end_date" name="end_date" >
        </div>

        <div class="form-group">
            <button type="submit" name="stud_asset">Reserve</button>
        </div>
    </form>

<?php
if (isset($_POST['stud_asset'])) {
    echo('hello');

    $id = $_GET['id'];
    $studentId = $_POST['student_id'];
    $start_date = $_POST['start_date'];
    $end_date = $_POST['end_date'];
    $status="Pending";

    $insertQuery = "INSERT INTO asset(stud_ID, asset_ID, r_start_date, end_date, status) VALUES ('$studentId', '$id', '$start_date', '$end_date', '$status')";
    if (mysqli_query($conn, $insertQuery)) {
        echo "<script>alert('Asset reserved successfully!'); window.location='student_asset.php';</script>";
    } else {
        echo "<script>alert('Failed to add asset.');</script>";
    }
}
mysqli_close($conn); 
?>

these are the codes and for your information, even the echo does not work. so i need help to figure out where does the error come from. i have connect to database at the start of the code.