One sample is about the Client-Side Callback using the parameter, called by the HTML Input button running on the server side. The other example is about creating the custom database control that can be called from ObjectDataSource and perform general database operations with no line of codes. I studied both samples taking a lot of time. As the database was missing in those sample codes, I used a sample table from SQL Server 2005, tested that all the data layer codes worked normally with the regular 2.0 controls, and applied them to the samples codes. To my great disappointment, both pages showed the errors and I could not find any solutions to let the pages work.
After quite a while, I decided to reconstruct the screwed-up pages. While leaving the normally compiled custom classes intact (for future references), I commented out all the code lines on the page sides, and wrote my own simple codes to reproduce the similar situations. For the Client Side Callback, I found out that, you can use the HTML Input button running on the server side to call any Callback codes that worked well with the client side buttons.
As for the Custom DataBase control, I could get exactly the same result as this control was supposed to achieve by using ObjectDataSource, GridView and DetailView controls. Through this process, I have learned how to combine ObjectDataSource with the custom class.