ASP.NET AJAX allows you to:

• Create next-generation interfaces with reusable AJAX components.
• Enhance existing pages using powerful AJAX controls with support for all modern browsers.
• Access remote services and data from the browser without tons of complicated script.

AJAX components in ASP.NET integrate cross-browser script libraries with the ASP.NET server side Web application framework. This integrated architecture empowers developers to rapidly create pages with sophisticated, responsive user interfaces and more efficient client-server communication by simply adding a few server controls to their pages.
In this web site the following AJAX server controls have been utilised:

• CollapsiblePanel : The CollapsiblePanel is a very flexible extender that allows you to easily add collapsible sections to your web page.
  We have used the collapsible panel as a container for all core content on this web site. This allows the flexibility to ‘roll-up’, i.e. hide any content as we require. The user then has the ability to ‘roll-down’, i.e. view, any content that they choose to.
• Confirm Button: ConfirmButton is a simple extender that catches clicks on a button (or any instance of a type derived from Button) and displays a message to the user.
  When a logon attempt is made with invalid credentials we use this extender to display an invalid logon message. We want the user’s attention to be totally focused on the fact that they entered invalid logon credentials. To this end, we use this extender to grey out the web page in the background, and display a confirm message to the user.
• ValidatorCallout : ValidatorCallout is an ASP.NET AJAX extender that enhances the functionality of existing ASP.NET validators.
  We have used this extender to validate any input entered by the user. For example on the ‘Contact Us’ web page it is mandatory to enter an email address, first name, surname, and comments. The ValidatorCallout extender is used to display messages to the user, in the form of popups, next to the data entry boxes, letting the user know that required fields are missing. The email address is also validated to ensure it has correct syntax of a valid email address.
• DynamicPopulate : DynamicPopulate is a simple extender that replaces the contents of a control with the result of a web service or page method call, i.e. it displays updated content without refreshing the whole web page.
  We use this control where ever possible to update components of a web page without updating the whole page. This minimises the amount of information transmitted through the internet, subsequently allowing the users interaction with the web site to run faster. An example of where we have used this is the conformation message after ‘Send’ has been initiated on Contact Us web page. The success or failure of the contact us information being sent is displayed to the user. Only this message is updated from the server, the remainder of the page is not changed.