There are many cases where hierarchical lists are useful or even necessary. One example is a quote database with nested categories. Because each category has its own subcategory, the database must be queried each time the user chooses a category, and this used to require a page reload in the past. Nowadays Ajax to the rescue !
jQuery makes Ajax coding very easy. The simplest way to use Ajax with jQuery is by using the function load() which is what I’ll use in this tutorial.

