AJAX indicator using jQuery

http://jquery-howto.blogspot.com/2009/04/display-loading-gif-image-while-loading.html

$("#btnLoad").click(function(){
    // Make AJAX call
    $("#content").load("http://example.com");
});

The above code loads contents from http://example.com into the <div id="content">. While the page is being loaded we want to display our animated GIF image in the “content”. So we could further improve our code like so:

$("#btnLoad").click(function(){

  // Put an animated GIF image insight of content
  $("#content").empty().html('<img src="loading.gif" />');

  // Make AJAX call
  $("#content").load("http://example.com");
});