index.php

<html>

<head>
	<meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no">
	<script src="scripts/material.min.js"></script>
	<link href="https://fonts.googleapis.com/css?family=Product+Sans:500,700&display=swap" rel="stylesheet">
	<link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
	<link rel="stylesheet" href="styles/material.min.css">
	<link rel="stylesheet" href="styles/main.css">
	<link rel="icon" type="image/png" href="images/logo.png">
	<title>Student Login | Feedie</title>
</head>

<body class="mdl-demo mdl-color-text--grey-900 mdl-base mdl-grid mdl-grid--no-spacing mdl-layout mdl-js-layout">
	<section class="horizontal-banner mdl-grid mdl-grid--no-spacing mdl-cell mdl-cell--12-col-desktop mdl-cell--8-col-tablet mdl-cell--4-col-phone">
		Horizontal banner
	</section>
	<section class="mdl-cell mdl-cell--6-col-desktop mdl-cell--8-col-tablet mdl-cell--4-col-phone section--center mdl-grid mdl-grid--no-spacing">
		<form action="" method="post">
			<div class="mdl-grid mdl-grid--no-spacing">
				<h4 class="mdl-cell mdl-cell--12-col questions">Student sign in</h4>
				<div class="mdl-cell mdl-cell--12-col questions" style="flex-direction: column;">
					<div class="mdl-textfield mdl-js-textfield mdl-textfield--floating-label">
						<input class="mdl-textfield__input" type="text" name="rollno" id="rollno">
						<label class="mdl-textfield__label">Register number</label>
					</div>
					<div class="mdl-textfield mdl-js-textfield mdl-textfield--floating-label">
						<input class="mdl-textfield__input" type="password" name="password" id="password">
						<label class="mdl-textfield__label">Password</label>
						<span onclick="toggler()" class="mdl-button mdl-js-button mdl-button--icon mdl-button--accent">
							<i id="sp" class="material-icons">visibility_off</i>
						</span>
					</div>
				</div>
				<div class="mdl-cell mdl-cell--12-col questions">
					<button type="submit" class="mdl-button mdl-js-button mdl-button--raised mdl-button--accent">
						Log in
					</button>
				</div>
				<script>
					function toggler() {
						if (document.getElementById("sp").innerHTML == 'visibility_off') {
							document.getElementById("sp").innerHTML = 'visibility';
							document.getElementById("password").type = "text";
						} else {
							document.getElementById("sp").innerHTML = 'visibility_off';
							document.getElementById("password").type = "password";
						}
					}

				</script>
				<div class="mdl-cell mdl-cell--12-col mdl-color-text--red-a400 questions">
					<?php
							if (isset($_GET["logout"])){
								if ($_GET["logout"] == 1){
									session_start();
									include('done_check.php');
									session_destroy();
								}
							}
							session_start();
							if (isset($_SESSION["st_username"])){
								//Add sleep here
								header('Location: dashboard/');
							}
							$servername = "127.0.0.1";
							$username = "root";
							$password = "";
							$dbname = "feedie_base";
							if (isset($_POST["rollno"]) AND isset($_POST["password"])){
							// Create connection
								$conn = new mysqli($servername, $username, $password, $dbname);
								$rollno = $_POST["rollno"];
								$sql = "SELECT st_username, password, class FROM students WHERE rollno = '".$rollno."'";
								$result = $conn->query($sql);
								if ($result->num_rows > 0) {
									// output data of each row
									$row = $result->fetch_assoc();
									if( $_POST["password"] == $row["password"] ){
										echo "Logging you in..";
										session_start();
										$_SESSION["rollno"] = $_POST["rollno"];
										$_SESSION["st_username"] = $row["st_username"];
										$_SESSION["class"] = $row["class"];
										header("Location: dashboard/"); // lines
									}
									else
										echo "Password incorrect!";
									}
								else {
										echo "Unknown Register number!";
								}
								$conn->close();
							}
						?>
				</div>
			</div>
		</form>
	</section>
</body>

</html>