Server Error in '/' Application.

Value cannot be null.
Parameter name: input

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentNullException: Value cannot be null.
Parameter name: input

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:


[ArgumentNullException: Value cannot be null.
Parameter name: input]
   System.Text.RegularExpressions.Regex.IsMatch(String input) +7829510
   WebClient.Home.Page_Load(Object sender, EventArgs e) in E:\CHINHNB\WebPhuNu.net\PhuNu4\WebPhuNu\WebClient\Home.Master.cs:52
   System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +25
   System.Web.UI.Control.LoadRecursive() +71
   System.Web.UI.Control.LoadRecursive() +190
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3064


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1008