Output Parameter In SP Not Working?

Hi everyone,

   This is the sp i have written which works fine in the sql server management studio when i run it but when i call it from the vb.net web application the output parameters are generated as nothing but the sp return the data from the select statement, so here is the sp followed by vb.net code to access the sp. 

This is the Store ProcedureCREATE PROCEDURE [dbo].StaffAuthenticate
@Staff_ID nvarchar(50),
@Password nvarchar(15),
@IsAuthenticated int OUTPUT,
@P_message_code int OUTPUT
AS
BEGIN
SET NOCOUNT ON;
Select * From Staff;
SET @IsAuthenticated = 0;
SET @P_message_code = 100;
RETURN END
GOThis is the VB.NET code.  Dim ConStr As String = GenericDataAccess.GetConnection(IConnectionStrNames.OAAStaffAuthStr)
Dim Conn As SqlConnection = New SqlConnection(ConStr)
Dim Command As SqlCommand = Nothing
Conn.Open()
Command = New SqlCommand()
Command.Connection = Conn
Command.CommandText = "StaffAuthenticate"
Command.CommandType = CommandType.StoredProcedure

Command.Parameters.Add("@Staff_ID", SqlDbType.NVarChar, 50).Value = UserId
Command.Parameters.Add("@Password", SqlDbType.NVarChar, 15).Value = Password
Command.Parameters.Add("@IsAuthenticated", SqlDbType.Int).Direction = ParameterDirection.Output
Command.Parameters.Add("@P_message_code", SqlDbType.Int).Direction = ParameterDirection.Output

Dim myDataReader As SqlDataReader = Command.ExecuteReader()
Dim Res As New StringBuilder

While (myDataReader.Read())
For i As Integer = 0 To myDataReader.FieldCount - 1
Res.Append(myDataReader(i).ToString())
Res.Append(" ; ")
Next
Res.AppendLine()
End While

MsgBox(Command.Parameters("@IsAuthenticated").Value)
MsgBox(Command.Parameters("@P_message_code").Value)
MsgBox(Res.ToString, MsgBoxStyle.Information, "DAL : StaffSqlAuthenticate")  Thanks for all the help, Really could use one. Kabir