为什么我不能将变量（会话）传递给php中同一页面的重载？

Question

This code should take the id of the div when I clicked on button inside this div. Then it should echo this id, I have many divs each with different id.

The program works correctly when I press on first div (it reloads the page and pass the id variable as global variable and then echo it), but the code does not work correctly when I press on another div (it did not pass the id variable as session variable).

javascript code:

var javascriptVariable = this.id;
document.getElementById('adcode').value = this.id;

alert(javascriptVariable );

php code:

echo "<form action='personalpage13.php'>";
echo"<input type='submit'  style='display:none;' class='b1'  value='b1' id=".$x.">";
echo"<br />";
echo"<input type='hidden'  name='adcode' id='adcode'/>";
echo" <br />";

$_SESSION["bb"] =$_GET['adcode'];
$d =$_SESSION["bb"] ;
echo"</form>";

and this to get the id var on reload of the same page:

$e=$_SESSION["bb"];
echo $e;

Answer 1

Before to use a $_SESSION variable you need to call session_start() function:

<?php
  session_start();
  $_SESSION['bb'] = 'anyvalue';
?>

after, when you need this value in other script:

<?php
  session_start();
  print $_SESSION['bb'];
?>