ADO/ADO.NET - Error while executing EXECUTESCALAR sql command

I get following error when I execute following piece of code.

Error : "executescalar requires the command to have a transaction when the connection assigned to the command is in a pending local transaction"

Code: public int GetStudentId(int studid)
         {
            try
            {
                int studentId= 0;
                using (SqlCommand command = new SqlCommand())
                {
                    command.Connection = connection;
                    command.CommandType = CommandType.StoredProcedure;
                    if (connection.State != ConnectionState.Open) { connection.Open(); }

                    command.CommandText = "TestStoredProcedure";
                    command.Parameters.Add(new SqlParameter("@StudentId", studid));
                    Object temp = new Object();
                    temp = command.ExecuteScalar();
                    if (temp != null)
                    {
                        studentId= (int)command.ExecuteScalar();
                    }
                    else
                    {
                        studentId= 0;
                    }
                }
                return studentId;
            }
            finally
            {
                if (connection.State == ConnectionState.Open) { connection.Close(); }
            }
        }
I get error only in few cases, sometime it works fine. I am not getting how to track the exact issue? Can any one help me to identify the exact issue?? Is there is any issue with code??

Thanks in advance 

You have to assign the Transaction object to the SqlCommand Object. Please check this example http://stackoverflow.com/questions/10648718/executenonquery-requires-the-command-to-have-a-transaction-error-in-my-code

Hello Hemanth,

Thanks for your reply.
Reason for the issue was SQL connection with begin transaction was not committed & closed in other method, as result when execution flow come to my method same earlier SQL connection (Of previous method) was getting used.
Hence I was getting error.

Regards,
Rajendra