Stored Procedure Output parameter

Hello,

I have a stored procedure Member_data that has only 1 output parameter. Below is the stored procedure code.

ALTER PROCEDURE usp_MemberData (@Mem_Name varchar(50) OUTPUT)
AS
BEGIN
SELECT
	@Mem_Name = Mem_Name
FROM
	UnitedDiningClub.dbo.UDC_Member

END
GO
EXEC usp_MemberData ''

GO

Now I have a method in c# that accesses the procedure but it is giving me the following error: "Procedure or function 'usp_MemberData' expects parameter '@Mem_Name', which was not supplied."

Here is the method:

public DataSet GetMembers()
        {
            DataSet myDataSet = new DataSet();
            SqlCommand cmdMembers = new SqlCommand();
            cmdMembers.CommandText = "usp_MemberData";
            cmdMembers.CommandType = CommandType.StoredProcedure;
            cmdMembers.Connection = jadcoreConnection.GetConnection();

            SqlDataAdapter mySqlDataAdapter = new SqlDataAdapter(cmdMembers);
            mySqlDataAdapter.Fill(myDataSet);                                //error begins here
            return myDataSet;
        }