The purpose of the book is to teach developers how to build custom controls for ASP.NET, the most flexible Web application. This topic is difficult to master because of the paradigm shift between ASP 3.0 and coding in ASP.NET. Specifically the reader will learn the difference between user controls and server controls and how to build each. Extending existing classes for their controls, such as DropDownList, or a DataGrid will be covered. This book will include the source code and explanations for the DotNetJunkies Web Tools Suite, which includes several custom controls.