System services are automatically installed when the Application Object Server is installed and are available when the AOS instance is running. They are written by Microsoft in managed code and hence they cannot be customized.
As mentioned, there are three system services, as follows:
User session service
We will have a detailed discussion of these later in the chapter. We will not be able to go into every detail of all service operations, but it will be more than enough to get you started. Fortunately, for those who want to dig deeper, these services are well documented on MSDN.
A combobox containing the Contoso Video Rental queries
A DataGridView control to contain the resulting data
Previous page and Next page buttons to provide paging of the result...