title: jQuery ajax security
body: <p>I have the following ajax call which checks to see if the user is a paid member, if yes it runs certain functions accordingly. This works but i'm concerned about security. What if someone alters this ajax code in console forcing <code>#button</code> to run the functions in success without having to do any post. Can i prevent this while still using jQuery ajax.</p>
  
  <pre><code>$('#button').click(function() {
      $.ajax({
          url:'checkplan',
          type:'POST',
          success:function(data){
              if(data == 'paid')
                  //grant access and run some functions
      }
  })
  </code></pre>