The demo shows the two ways of server-side binding of 
RadDataForm:       
- Using declarative DataSource control by setting DataSourceID property - you can bind a DataForm to various data source controls such as SqlDataSource, ObjectDataSource, XmlDataSource, etc.
- Using the NeedDataSource event in the code-behind where the DataSource is specified - The key to the dynamic data binding of Telerik RadDataForm is handling correctly the     NeedDataSource event. That's why we chose this exact name. 'Need' in this case actually means that if at an exact moment the data source property does not     point to a valid data source object, the control will not behave correctly. 
     The advantages of using 
NeedDataSource event are that the developer does not need to write     any code in order to handle the logic about when and how the data-binding should be processed. In the code of the 
NeedDataSource handler you should prepare the data source     or custom list of objects for 
Telerik RadDataForm and assign it to the controls's 
DataSource     property.