Name Does Not Exist in Current Context Error

I tried to build the following code and received and error - Name Does Not Exist in Current Context for the following:  'Server', 'Request', 'Decrypt', 'spencode', FormsAuthentication'

 Any assistance is greatly appreciated.

 

using System;

using System.Collections.Generic;

using System.Text;

using System.Web;

using System.Web.UI;
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