Using jQuery .ajax for a voting script. How do I update MySQL DB after successful vote?

I'm assuming I have to put something in the success option. However what I have isn't working.

I declare this JS function on the page:

<script type="text/javascript">
 function performAjaxSubmission() {
        $.ajax({
          ur开发者_StackOverflow中文版l: 'addvotetotable.php',
          method: 'POST',
          data: {
          },
          success: function() {
          }
        });

      }
</script>

Then in the ajax call which is working properly I declare this for the success:

success: function(data) {

            performAjaxSubmission();
},

addvotetotable.php looks like:

<

?php
// If user submitted vote give the user points and increment points counter

require_once("models/config.php");

//Check to see if there is a logged in user
    if(isUserLoggedIn()) { 
    $username_loggedin = $loggedInUser->display_username;
    }

    if (strlen($username_loggedin)) { 
    include_once "scripts/connect_to_mysql.php";
    $query = mysql_query("SELECT vote FROM points_settings WHERE id=1")or die (mysql_error());
    while($info = mysql_fetch_array($query)){

            $points_value=$info['vote'];
    }
     include_once "scripts/connect_to_mysql.php";
        $query = mysql_query("INSERT INTO points (id,username,action,points) VALUES ('','$username_loggedin','vote','$points_value')")or die (mysql_error

());
        include_once "scripts/connect_to_mysql.php";
        $query = mysql_query("UPDATE userCake_Users SET points=points + $points_value WHERE Username='$username_loggedin'")or die (mysql_error());
    }

    ?>

You have to provide a value that you want to store in your database in the "data" of the ajax-request. Than you can use this in your php-code using $_POST["something"], check if it's valid... and return f.e. html or json which you than handle in the success-function.

<script type="text/javascript">

 function onSubmitVote() 
 {

        $.ajax({
          url: 'addvotetotable.php',
          method: 'POST',
          data: "theVoteValue=" + <read_your_vote_value_here>,
          success: function(result) {
          >>>return something in your addvotetotable.php which indicate success and show a message whether the vote was successful or not.<<<
          }
        });

        return false; // prevent submit if it is a submit-type button.

}
</script>

What this does is post data of the vote (it's value) to the php-file. There you can read it with $_POST["theVoteValue"] and put it in the database. You check if the value is valid and may insert, else you return an error-message or something so that in javascript you can notify the user of it's failure.