是否可以在PHP中禁用刷新按钮？

-1

我创建了一个在线考试..我有我的计时器30分钟它会自动提交考试，但每次页面刷新或重新加载时间在30分钟恢复有什么办法来预防它？在此先感谢是否可以在PHP中禁用刷新按钮？

<?php 
session_start(); 
if (isset($_SESSION['targetdate'])) { 
    // session variable_exists, use that 
    $targetDate = $_SESSION['targetdate']; 
} else { 
    // No session variable, red from mysql 
    $result=mysql_query("select * from test where testid='29' LIMIT 1"); 
    $time=mysql_fetch_array($result); 
    $dateFormat = "d F Y -- g:i a"; 
    $targetDate = time() + ($time['duration']*60); 
    $_SESSION['targetdate'] = $targetDate; 

} 

$actualDate = time(); 
$secondsDiff = $targetDate - $actualDate; 
$remainingDay  = floor($secondsDiff/60/60/24); 
$remainingHour = floor(($secondsDiff-($remainingDay*60*60*24))/60/60); 
$remainingMinutes = floor(($secondsDiff-($remainingDay*60*60*24)-   ($remainingHour*60*60))/60); 
$remainingSeconds = floor(($secondsDiff-($remainingDay*60*60*24)- ($remainingHour*60*60))-($remainingMinutes*60)); 
$actualDateDisplay = date($dateFormat,$actualDate); 
$targetDateDisplay = date($dateFormat,$targetDate); 

?> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
<title>Untitled Document</title> 
<script type="text/javascript"> 
var days = <?php echo $remainingDay; ?> 
var hours = <?php echo $remainingHour; ?> 
var minutes = <?php echo $remainingMinutes; ?> 
var seconds = <?php echo $remainingSeconds; ?> 
function setCountDown() 
{ 
seconds--; 
if (seconds < 0){ 
    minutes--; 
    seconds = 59 
} 
if (minutes < 0){ 
    hours--; 
    minutes = 59 
} 
    if (hours < 0){ 
    hours = 23 
} 
    document.getElementById("remain").innerHTML = " "+hours+" hr "+minutes+" min "+seconds+" sec"; 
    SD=window.setTimeout("setCountDown()", 1000); 
    if (minutes == '00' && seconds == '00') { seconds = "00"; window.clearTimeout(SD); 
    window.location = "result.php" 
} 

    } 
</script> 

</head> 
<body onLoad="setCountDown();"> 
<div id="remain"><?php echo "$remainingHour hours, $remainingMinutes minutes,  $remainingSeconds seconds";?></div>

我只是复制该代码我想限制测验定时器仅30分钟，什么是$ _SESSION [“targetdate”]？

来源

2014-01-26 Willingtolearn

在浏览器更新你有什么样的代码？我只是无法看到具有该描述的图片。 –

可能重复的[如何使倒计时器不刷新页面重置]（http://stackoverflow.com/questions/11272190/how-to-make-countdown-timer-to-not-reset-on-page-刷新） –

是的先生，但我不明白$ _SESSION目标日期和测试数据库' – Willingtolearn