<?php
//Start a session
if(!isset($_SESSION)){
session_start();
}
if($_SESSION['email_address']==""){
$msg=base64_encode("Please Login");
header("Location:../../index.php?msg=$msg");
exit();
}
?>
<?php
require"../db/db_connection.php";
$_GET['email_address']=$_SESSION['email_address'];
date_default_timezone_set("Asia/Colombo");
$stime = date('Y-m-d H:i:s');
$sql = "SELECT c.course_name,c.course_id,su.subject_name,su.subject_id,ex.exam_paper_name,ex.exam_paper_id,ex.date_posted,ex.deadline FROM student s LEFT JOIN course c ON s.course_id=c.course_id LEFT JOIN subject su ON su.course_id=c.course_id LEFT JOIN exam_paper ex ON ex.subject_id=su.subject_id WHERE s.email_address='".$_SESSION['email_address']."' AND ex.status=1";
$query = mysqli_query($con,$sql);
?>
<html>
<head>
<meta charset="UTF-8">
<title>ITech Institute</title>
<link rel="stylesheet" type="text/css" href="../../css/admin_style.css">
<meta name="viewport" content="width=device-width,initial-scale: 1.0, user-scalabe=0" />
<link rel="stylesheet" type="text/css" href="../../font-awesome-4.6.3/font-awesome-4.6.3/css/font-awesome.css">
<script src="../../js/jquery.min.js"></script>
<script src="../../js/admin.js"></script>
<!-- For nice scroll start-->
<script src="../../js/jquery.nicescroll.js"></script>
<script src="../../js/style.js"></script>
<!-- nice scroll end-->
<!-- clock start-->
<script src="../../js/clock.js"></script>
</head>
<body>
<?php
include("../../include/internal_header.php");
?>
<!-- <div id="header">
<div class="logo"> <a href="#">Admin<span> Page</span></a></div>
</div>-->
<a class="mobile" href="#">MENU</a>
<div id="container">
<div class="sidebar">
<ul id="accordion" class="accordion" style="margin:0; padding:0;">
<li>
<div class="link"><i class="fa fa-dashboard"></i><a href="student_dashboard.php">Dashboard</a></div>
</li>
<li>
<div class="link"><i class="fa fa-globe"></i><a href="profile.php">Profile</a></div>
</li>
<li>
<div class="link"><i class="fa fa-globe"></i><a href="view_course.php">View Courses</a></div>
</li>
<li>
<div class="link"><i class="fa fa-globe"></i><a href="view_subject.php">View Subjects</a></div>
</li>
<li>
<div class="link"><i class="fa fa-globe"></i><a href="view_exam.php">Exam</a></div>
</li>
<li>
<div class="link"><i class="fa fa-globe"></i><a href="view_result.php">View Result</a></div>
</li>
<li>
<div class="link"><i class="fa fa-globe"></i><a href="signout.php">Log Out</a></div>
</li>
<li>
<div class="link"><form name="clock"><font color="white"><i class="fa fa-clock-o"></i>Time: <br></font> <input style="width:150px;" type="submit" class="trans" name="face" value="">
</form>
</div>
</li>
</ul>
</div><!--sidebar-->
<div class="content">
<div class="content_heading">
<p>View Exams</p>
</div><!--content_heading-->
<div class="div1">
<!--table start-->
<table>
<tr>
<td>Course Name</td>
<td>Subject Name</td>
<td>Exam Paper Name </td>
<td>Data Posted Name</td>
<td>Dead Line</td>
<td>Start Exam</td>
</tr>
<tr><?php while($row = mysqli_fetch_array($query)){ ?>
<td><?php echo $row["course_name"]; ?></td>
<td><?php echo $row["subject_name"]; ?></td>
<td><?php echo $row["exam_paper_name"]; ?></td>
<td><?php echo $row["date_posted"]; ?></td>
<td><?php echo $row["deadline"]; ?></td>
<td>
<a target="_blank" title="Start Exam" href="start_exam_paper.php?stime=<?php echo $stime;?>&exid=<?php echo $row['exam_paper_id'];?>&cid=<?php echo $row['course_id'];?>&suid=<?php echo $row['subject_id'];?>"style="visibility:<?php echo $_SESSION["Visibility"]; ?>">
<button id="btn-st">
<i class="fa fa-edit"></i> Start Exam
</button>
</a>
</td>
</tr>
<?php }?>
</table>
</div><!--div1-->
</div>
</div><!--div1-->
</div><!--content-->
</div><!--container-->
</body>
</html>
这是我的代码，我需要在点击后禁用“开始检查”按钮。学生不能重新记录并再次点击按钮，我的系统在检查系统中。我使用js但它不能正常工作。所以我需要验证到PHP
答案 0 :(得分：0)
if(!empty($_SESSION)){
echo ""; // Don't put here your login button.
}else{
echo " Your login button"; // Put here your login button.
}