Error Encountered While Executing A UDF

Hi,

I get the following error while trying to execute a UDF.

Msg 6522, Level 16, State 1, Line 1

A .NET Framework error occurred during execution of user defined routine or aggregate 'test':

System.NullReferenceException: Object reference not set to an instance of an object.

System.NullReferenceException:

at SalesCentral_Database.UserDefinedFunctions.udfTest()

My function is defined as follows:

Imports System

Imports System.Data

Imports System.Data.SqlClient

Imports System.Data.SqlTypes

Imports Microsoft.SqlServer.Server

Partial Public Class UserDefinedFunctions

<Microsoft.SqlServer.Server.SqlFunction(DataAccess:=DataAccessKind.Read)> _

Public Shared Function udfTest() As SqlString

SqlContext.Pipe.Send(System.DateTime.Now().ToString())

Dim conn As New SqlConnection("context connection=true")

conn.Open()

Dim cmd As New SqlCommand("SELECT MAX(ACCTPERIOD) FROM TBL_OPPORTUNITY_HIS", conn)

Return New SqlString(cmd.ExecuteScalar().ToString())

End Function

End Class

SQL Server

CREATE ASSEMBLY SalesCentral_Database from '\isew5l6c ranfSFS_SalesSalesCentral_Database.dll' WITH PERMISSION_SET = SAFE

CREATE FUNCTION test() RETURNS NVARCHAR(10) AS EXTERNAL NAME [SalesCentral_Database].[SalesCentral_Database.UserDefinedFunctions].[udfTest]

SELECT dbo.test()

- Here I get the error mentioned above. Can anyone please tell me what am I missing.

Thanks.