Hi Shafiq,
Yes, you can use PDF or XLS in ASP.NET. The code used in the Winforms examples for the PDF and XLS controls themselves is the same as you would use in ASP.NET.
Generally, .NET controls that do not have a GUI can be used in Webforms as well as Winforms. In VS2002 and VS2003, you can add the PDF and XLS controls to the toolbox and they will display with the other controls when you have the design view of your webform open. For VS2005 you can add the controls to the toolbox at any time when you have the webform's design view open, but you have to select View and Component Designer from the main toolbar in order to see the controls in the toolbox.
Suelinda Webster
Customer Engagement, ComponentOne LLC