title: pass string using jquery ajax to php
body: <p>I want to send a hash string to my php file. but failed, can anyone help me please?</p>
  
  <p>my javascript is like this:</p>
  
  <pre><code>var hashString = "#support_form";
  
  $.ajax ({
     type: "POST",
     url:"index.php",
     data: hashString,
     success: function() {
        console.log("message sent!");
     }
  });
  </code></pre>
  
  <p>and the php:</p>
  
  <pre><code>&lt;?php
  $theHash = $_POST['hashString'];
  ?&gt;
  </code></pre>
  
  <p>What should I do? Thanks</p>