I would like to share with you the following useful articles and FAQ's below about Dynamic Controls in ASP.NET:

Dynamically Creating controls in ASP.NET
http://support.microsoft.com/kb/317515
http://www.singingeels.com/Articles/Dynamically_Created_Controls_in_ASPNET.aspx

Truly Understanding Dynamic Controls
http://weblogs.asp.net/infinitiesloop/archive/2006/08/25/TRULY-Understanding-Dynamic-Controls-_2800_Part-1_2900_.aspx

Key to ensuring dynamic ASP.NET controls save Viewstate - level 300
http://codebetter.com/blogs/jeffrey.palermo/archive/2004/11/25/33584.aspx

FAQ: Why do dynamic controls disappear on postback and not raise events?
http://forums.asp.net/t/1186195.aspx

Adding controls to asp.net dynamically and persisting them
http://www.codeproject.com/KB/aspnet/dynamic_control_adding.aspx
http://www.igregor.net/post/2007/12/Adding-Controls-to-an-ASPNET-form-Dynamically.aspx