A rollover image or tooltip preview based on JQuery library - tooltip-like bubble popups that appears when you roll over link or a thumbnail. Included 3 examples of using this simple script.

Easy to use JQuery-based lightbox clone.

A lightweight (~4.5kb) JavaScript dialog box library. The script currently offers four dialog styles: alerts, warnings, prompts and success. There is nothing to add to your page except references to the JavaScript and CSS if you choose not to incorporate them in your existing files..

Partial-page rendering removes the need for the whole web page to be refreshed as the result of a postback. Instead, only individual regions of the page that have changed are updated. As a result, users do not see the whole page reload with every postback, which makes user interaction with the Web page more seamless.

Developers that want to add such behaviors to their web pages are often faced with a difficult decision. All of these actions can be implemented using a very simple solution: by refreshing the entire page in response to the user interaction. However this solution is easy but not always desirable. The full page refresh can be slow, giving the user the impression that the application is unresponsive. Another option is to implement such actions using JavaScript (or other client-side scripting technologies). This results in faster response times, at the expense of more complex, less portable code. JavaScript may be a good choice for simple actions, such as updating an image. However, for more complicated actions, such as scrolling through data in a table, writing custom JavaScript code can be a very challenging undertaking..

First things first, Asynchronous JavaScript and XML (AJAX) is not a technology. AJAX is a technique that has brought about a great change in the world of web development. The AJAX technique comes in response to the increasing demand of interactive web applications. With AJAX, web page exchange small amount of data with the server behind the scene. This means that every time a new piece of data is entered by the user, or there is a request for a change, the entire page does not have to be reloaded. Usability is also greatly affected thanks to AJAX..

Good article about practical using of Yahoo! UI javascript library. 15 code examples with demos are included.

Forms are easy enough to create when they are simple, like search boxes. But what if you need them to be complex? How about changing the forms based on input by the viewer? This is where interactive forms using Javascript and HTML can help. I'll use a simple example on how interactive forms can be useful.

The next generation of web apps make heavy use of JavaScript and CSS. We’ll show you how to make those apps responsive and quick.
With our so-called "Web 2.0" applications and their rich content and interaction, we expect our applications to increasingly make use of CSS and JavaScript. To make sure these applications are nice and snappy to use, we need to optimize the size and nature of content required to render the page, making sure we’re delivering the optimum experience. In practice, this means a combination of making our content as small and fast to download as possible, while avoiding unnecessarily refetching unmodified resources..

Learn how to write a basic, client-side Atlas progress bar, and download the source code.

You almost always want to have your form to be disabled as soon as the user pressed the submit button so that the user doesn't accidently submit the form twice. Here's how.