In our borrowing system, the HTML in the header is fixed

and does not change as the page jumps.

In order not to write the header code repeatedly, we need to make a head.php file

Write the header HTML code to facilitate calling in each file.

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<table width="" border="0" align="center" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC" >
  <tr>
    <td bgcolor="#FFFFFF"><img src="https://img.php.cn/upload/course/000/000/008/58215f071f35b180.jpg" width="440" height="200" /></td>
  </tr>
  <tr>
    <td bgcolor="#FFFFFF"><table width="440" height="50" border="0" align="center" cellpadding="0" cellspacing="0">
        <tr>
          <td align="center" background="https://img.php.cn/upload/course/000/000/008/58215f29827c0755.jpg">
          <a href="index.php" title="首頁">首頁</a></td>
          <td align="center" background="https://img.php.cn/upload/course/000/000/008/58215f29827c0755.jpg">
          <a href="index.php?proid=<?php echo urlencode('網(wǎng)頁美工');?>" title="網(wǎng)頁美工">網(wǎng)頁美工</a></td>
          <td align="center" background="https://img.php.cn/upload/course/000/000/008/58215f29827c0755.jpg">
          <a href="index.php?proid=<?php echo urlencode('大數(shù)據(jù)');?>" title="大數(shù)據(jù)">大數(shù)據(jù)</a></td>
          <td align="center" background="https://img.php.cn/upload/course/000/000/008/58215f29827c0755.jpg">
          <a href="index.php?proid=<?php echo urlencode('asp編程');?>" title="asp編程">asp編程</a></td>
          <td align="center" background="https://img.php.cn/upload/course/000/000/008/58215f29827c0755.jpg">
          <a href="index.php?proid=<?php echo urlencode('php編程');?>" title="php編程">php編程</a></td>
          <td align="center" background="https://img.php.cn/upload/course/000/000/008/58215f29827c0755.jpg">
          <a href="index.php?proid=<?php echo urlencode('軟件開發(fā)');?>" title="軟件開發(fā)">軟件開發(fā)</a></td>
          <td align="center" background="https://img.php.cn/upload/course/000/000/008/58215f29827c0755.jpg">
          <a href="landing.php"  title="用戶登陸">用戶登陸</a>&nbsp;&nbsp;
          </td>
        </tr>
      </table></td>
  </tr>
</table>

The user’s logout function is also added here:

<td align="center" background = "https://img.php.cn/upload/course/000/000/008/58215f29827c0755.jpg">
<a href="landing.php" title="用戶登陸">用戶登陸</a>&nbsp;&nbsp;
  <?php
  if ($_SESSION['id']){
    echo "<a href='landing.php?tj=out' title='退出'>退出</a>";
  }
  ?>
</td>

Make a judgment on the login function page

<?php
//初始化session
if(isset($_GET['tj']) == 'out'){
  session_destroy();
  echo "<script language=javascript>alert('退出成功！');window.location='landing.php'</script>";
}
?>