jQuery - Getting form values for ajax POST

I am trying to post form values via AJAX to a php file. How do I collect my form values to send inside of the "data" parameter?

$.ajax({
        type: "POST",
        data: "submit=1&username="+username+"&email="+email+"&password="+password+"&passconf="+passconf,
        url: "http://rt.ja.com/includes/register.php",
        success: function(data)
        {   
            //alert(data);
            $('#userError').html(data);
            $("#userError").html(userChar);
            $("#userError").html(userTaken);
        }
    });

HTML:

<div id="border">
  <form  action="/" id="registerSubmit">
    <div id="userError"></div>
      Username: <input type="text" name="username" id="username" size="10"/><br>
      <div id="emailError" ></div>
      Email: <input type="text" name="email" size="10" id="email"/><br>
      <div id="passError" ></div>
      Password: <input type="password" name="password" size="10" id="password"/><br>
      <div id="passConfError" ></div>
      Confirm Password: <input type="password" name="passconf" size="10" id="passconf"/><br>
      <input type="submit" name="submit" value="Register" />
  </form>
</div>

Solution 1:

Use the serialize method:

$.ajax({
    ...
    data: $("#registerSubmit").serialize(),
    ...
})

Docs: serialize()

Solution 2:

$("#registerSubmit").serialize() // returns all the data in your form
$.ajax({
     type: "POST",
     url: 'your url',
     data: $("#registerSubmit").serialize(),
     success: function() {
          //success message mybe...
     }
});

Solution 3:

you can use val function to collect data from inputs:

jQuery("#myInput1").val();

http://api.jquery.com/val/