Software developer can use System.Web.SessionState.HttpSessionState member Count which returns the number of items in the current session collection. Related TutorialsHow validation controls work in ASP.NET 4.0 How to use timeout property of the proxy class in C# How to document web service in ASP.NET in VB.NET How to use CompareValidator control in ASP.NET 4.0 How to create a Stylesheet in ASP.NET