这个PHP的语法错误[关闭]

this code is providing me with a syntax error on the line with 'else' on it. Any suggestions, thanks!

<?php
if($_SESSION['id'])
echo '<div id="center" class="column">';
include("center.php");
echo'</div>
<div id="left" class="column">';
include("leftbar.php");
echo'</div>
<div id="right" class="column">';
include("rightbar.php");
echo '</div>';
else
echo '<h1>Staff please, <a href="index.php">login</a> 
before accessing this page, no access to students.</h1>';
?>

Yes, my suggestion is to use brackets. Right now your code basically reads like this:

<?php
if($_SESSION['id']) {
    echo '<div id="center" class="column">';
}
include("center.php");
echo'</div>
<div id="left" class="column">';
include("leftbar.php");
echo'</div>
<div id="right" class="column">';
include("rightbar.php");
echo '</div>';
} else {} <--- error is here because there is no open if statement since you didn't use brackets
echo '<h1>Staff please, <a href="index.php">login</a> 
before accessing this page, no access to students.</h1>';
?>

Note that since you didn't use brackets, your if conditional only applies to the following line of code. When the parser hits the else line there is no open if condition for the else to be related to.

Your code should read like this:

<?php
if($_SESSION['id']) {
    echo '<div id="center" class="column">';
    include("center.php");
    echo'</div><div id="left" class="column">';
    include("leftbar.php");
    echo'</div><div id="right" class="column">';
    include("rightbar.php");
    echo '</div>';
} else {
    echo '<h1>Staff please, <a href="index.php">login</a> before accessing this page, no access to students.</h1>';
}
?>

You need to put them inside a block. Block starts with { and ends with }.

if($_SESSION['id']) {
  echo '<div id="center" class="column">';
  include("center.php");
  echo'</div>
  <div id="left" class="column">';
  include("leftbar.php");
  echo'</div>
  <div id="right" class="column">';
  include("rightbar.php");
  echo '</div>';
}
else {
  echo '<h1>Staff please, <a href="index.php">login</a> 
  before accessing this page, no access to students.</h1>';
}

P.S.: I'd suggest to use isset() inside the if condition. Like so:

if( isset($_SESSION['id']) ) {