We want to design a commenting system where visitors of your website can leave a comment on a news post. The form for submitting a comment should only be visible when a “post comment button” is clicked.

We’ll begin with the complete HTML and JavaScript code for our first application, a simple web page that displays the decimal value of any character. Then we’ll break apart the JavaScript and examine it.

In this tutorial I’ll show you a simple method to pass any HTML form through AJAX without the need to hard code all form fields into the JavaScript or Server Side Script.

In the past, web applications were limited because a web page had to be reloaded (or another page loaded in its place) in order for new data to be obtained. Other methods were available (without loading another page), but the techniques weren’t well supported and had a tendency to be buggy.

You might have been in a situation before where you had a list of items in your database that needed to be output in a specific order. These items could be anything: perhaps a listing of your favourite movies or your favourite books.

When you click on a link, an interstitial page (usually an advert) appears before you are shown the new page that you clicked to view. doInterstitial() is a simple javascript function that rewrites all links on a page.