Question

When I run the code the click event works the first time. When I click it more then one time it seems that the click even has unbounded. How do I keep the click event bounded?

var Categories = function() {
        $("select[id^='CategoryListBox-']").click(
        function() {
            SelectedItem = $(this).val();
            $(this).parent().load('/Categories/CategoryPicker?CatID=' + SelectedItem);

            //send CatID to the requesting page
            $('form#SubmitPost').prepend('<input id="CatID" name="CatID" type="hidden" value="' + SelectedItem + '" />');
        });
    }

    Categories();

Answer 1

It looks like you are using AJAX to load new HTML from the server and you’re overwriting the existing select box with a new one. This will remove event listeners. One solution is to use live():

$("select[id^='CategoryListBox-']").live("click", function() {
  SelectedItem = $(this).val();
  $(this).parent().load('/Categories/CategoryPicker?CatID=' + SelectedItem);

  //send CatID to the requesting page
  $('form#SubmitPost').prepend('<input id="CatID" name="CatID" type="hidden" value="' + SelectedItem + '" />');
});

One suggestion: don’t use an attribute selector like this. Give all the relevant select boxes a class like “category” and then do:

$("select.category").live("click", function() { ... }

It’s much faster.

Lastly, this is a better way of creating your hidden inputs:

$("<input>").attr({id: "CatID", name: "CatID", type: "hidden", value: SelectedItem}).prependTo("#SubmitPost");

The reason being that this creates the DOM element directly rather than interpreting HTML, which again is much slower.