A typical challenge when using ASP.NET AJAX is the fact that the AJAX behavior of the page (which controls initiate AJAX requests and update other controls) is achieved by setting numerous controls individually.

For example, in certain frameworks you need to triggers that initiate AJAX callbacks upon predefined conditions. For example:

• "Message Body" UpdatePanel - Trigger 1: The needs to be updated when an e-mail item is clicked

• "Message Body" UpdatePanel - Trigger 2: The needs to be updated when the calendar is clicked

• "E-mail list" UpdatePanel - Trigger 1: The needs to be updated when the calendar is clicked

The combination of these 3 Triggers define the 2 AJAX relations on the page, which are:

1. When the calendar is clicked the e-mail listand the messagebodyneed to be updated

2. When an e-mail messageis clicked the message bodyonly needs to be updated

As you can see, it is not very easy to figure out what will be the effect of the combination of triggers, especially when you have complex real-life applications like the Telerik HelpDesk sample. This task would require placing 20+ Update Panels and setting numerous triggers.

Moreover, setting several triggers that facilitate every of the numerous AJAX relations will definitely need serious planning and probably something like a "Trigger diagram".

In contrast, the Telerik RadAjax framework offers a centralized place where you can define and modify the AJAX relations on the page. This is done through the single configuration dialog of the AJAX Manager in Visual Studio .Net design mode.

If we need to implement the above scenario we need to simply set the two relations in the dialog.

Relation 1: When the calendar is clicked the e-mail listand the messagebodyneed to be updated

Relation 2: When an e-mail messageis clicked the message bodyonly needs to be updated

It is clearly of benefit for developers to be able to see all AJAX relations at a glance in one centralized place (the AJAX Manager dialog) , rather than having to configure every Trigger of every UpdatePanel individually.

The logic for setting AJAX relations in the AJAX Manager dialog leads to another benefit - the AJAX relations are defined in the same sequence in which users interact with the interface of the application.