JQuery :: Sending Html Form Data To Php File And Getting Returned Results?

I have a html form which produces 3 post varaibles.

I'd link to be able to call a php file when sumbitted that sends the data from my form and returns the results from my php file to a div on the oringal page.

I know that you can use .load to call a page to be diaplayed within a div $('#container').load('url #div_on_page') but dont know how to send the from data.

this is the code.

<form method="post" id="new_user_form" >
<input type="text" name="newuser" />
<br /><br />
<input type="password" name="newpassword1" />

[Code].....