Add AJAX Request to Google Analytics

If you use jQuery you can bind to the global AjaxComplete event to fire a Pageview everytime an Ajax call completes:

jQuery(document).ajaxComplete(function(e, xhr, settings){
  var d = document.location.pathname + document.location.search + document.location.hash;
  _gaq.push(['_trackPageview', d]);
});

Source: http://stackoverflow.com/questions/7737549/google-analytics-and-loading-a-page-using-ajax-get-request

Useful jQuery Tips

Check if a checkbox is checked:
if($('#checkbox').is(':checked')) ...

Check if a select option is selected:
if($('#select option:selected').length()) ...

Get the selected radio value:
$('.radio:checked').val()

Get all inputs with a classname begins with rescheck:
  $("input[class^=rescheck-]").each(
    function() {
      alert($(this).attr('class'));
    }
  );

Jump to ( Scroll To ) an element:
$('html, body').animate({ scrollTop: $("#some_element").offset().top }, 500);

Checking to see if there is an attribute on an element:
var attr = $(this).attr('name');
if (typeof attr !== 'undefined' && attr !== false) {}

Clear selection on select:
$("#my_select option:selected").removeAttr("selected");

Ajax request and putting the result array into a select:

  $.post("/url", function(data) {
    var selected = '';
    $.each(data, function(key, data) {
      $('#foobar').append("" + data + "");
    });
  });

Allow Only Numbers (0-9) in Input Fields with jQuery

  $(".numbersOnly").keydown(function(e){
    var key = e.charCode || e.keyCode || 0;
    // allow backspace, tab, delete, arrows, numbers and keypad numbers ONLY
    return (
        key == 8 || 
        key == 9 ||
        key == 46 ||
        (key >= 37 && key <= 40) ||
        (key >= 48 && key <= 57) ||
        (key >= 96 && key <= 105));
  });

Avoid Scrollbars when using JQuery Accordion

Use the fillSpace and clearStyle options and set them to TRUE.

$("#accordion").accordion({
    fillSpace: true,
    clearStyle: true
});