Passing Data To Server And Updating Asynchronously?

Basically I have a site where I want the user to input something, have it go to the server for processing and then return it asynchronously, load the contents into a div and then fade it in with jQuery. What is the best way to the do accomplish this?

Currently here is my "solution":

$(document).ready(function () {
$('#output-box').hide();
$('#form1').submit(function () {
$.ajax({
type: "POST",
url: "Default.aspx/ParseData",
data: "{ $('#txtInput').val() }",
success: function (msg) {
$('#output-box').text(msg).fadeIn();
}
});
return false;
});
});

It doesn't work - just returns the contents of Default.aspx. So how do I properly send the contents of #txtInput to the ParseData function in Default.aspx.vb? Also, is this the best way to accomplish something like this? Should I even need to use jQuery to send the data, or should I simply call the function and have it grab the data server-side, put in the information in the result div, and then show it using jQuery?