Display Circular Progress Indicator Using Jquery When Textbox Textchange Event Occurs

I want to display a circular progress indicator using jquery in asp.net when textbox textchange event occurs.when user enters some value in a textbox and textchange event occurs or when user loses the focus on that textbox,system checks values in databases.I want to give user a progress indicator type when query is in progress, how can i accomplish with jquery. i am pasting a little code here.

$("#Txturl").blur(function() {
$.ajax({
type: "POST",
url: "Default.aspx/Getvalue",
data: "{}",
contentType: "application/json; charset=utf-8",
dataType: "json",
async: true,
success: function(msg) {
///to to do here? i ve no idea;
}
});
return false;
});