Straight to your questions:
- The set_value and set_content methods are not the same. The first one sets a value which is associated with the tooltip in order to extract it later and determine what content to load. The set_content method actually sets content of the tooltip.
- The data is actually taken in the WebService method. What is done there is that the value which was set to the tooltip is extracted and used as a primary key to determine what exact information should be taken from the database.
We understand that some of the demos are a little bit complex and viewing only a few of their files is not enough to understand the scenario. That is why when you install RadControls, our online examples projects are automatically installed on your computer and you can not only examine their full source code, but also extend them further in order to meet your requirements.
You can open the demos from here:
Start\Programs\Telerik\RadControls for ASPNET AJAX\Open Sample WebSite In VisualStudio
The actual location on your hard disk is the following one:
C:\Program Files\Telerik\RadControls for ASPNET AJAX \Live Demos
I hope that this information is helpful and examining the full source code will help you get a better understanding on the setup.
the Telerik team