php - jquery .post not working -

i working following code:

action.php

<?php $_session['passtext'] = $_post['passtext']; ?> 

index.php

<script type="text/javascript"> $(function(){     $("#clickable").click(function() {         $.post("action.php", { passtext: "hello" } );         alert('refresh page see session text');     }); }); </script>  <a href="javascript:void(0);" id="clickable">click me set session text</a>  <?php if(isset($_session['passtext'])) echo $_session['passtext']; ?> 

when click link, alert, seems action.php isn't running @ -- because refresh page , see no echo of $_session['passtext'] (it isn't being set)

there no errors in error console either

what missing?

you need add line @ beginning of files before deal sessions:

session_start(); 

from php docs:

session_start() creates session or resumes current 1 based on session identifier passed via or post request, or passed via cookie.