Stored Procedure '' Not Found

Hello,
 I try to use Stored Procedure with SQL Server 2005. I was created a new procedure in my dbb "GetIDTransaction"
 set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:<Author,,Name>
-- Create date: <Create Date,,>
-- Description:<Description,,>
-- =============================================
ALTER PROCEDURE [dbo].[GetIDTransaction]
-- Add the parameters for the stored procedure here
@DateTransation NVarChar(50),
@ID int OUTPUT
AS
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.

INSERT INTO Transactions_Guichet (DateTransaction, RefExpay,Montant,AccesRestreint,Valide,AdresseEmail,ClePerso,RemonteeBackOffice) VALUES(@DateTransation,'', '0','0','0','','','')
SET @ID=SCOPE_IDENTITY()
RETURN

  
in  
 SqlConnection oConnection = new SqlConnection(strConString);
SqlCommand oCommand = new SqlCommand("GetIDTransaction", oConnection);
oCommand.CommandType = CommandType.StoredProcedure;
//Création de la dateTransaction
SqlParameter oParam = oCommand.Parameters.Add("@DateTransation", SqlDbType.DateTime, 8, "DateTransation");
oParam.Value = DateTime.Now.ToString();

SqlParameter oParam2 = oCommand.Parameters.Add("@ID", SqlDbType.Int, 0, "IdTransaction");

oParam2.Direction = ParameterDirection.Output;
//Ouverture de la connection
oConnection.Open();

//Récupère Id
oCommand.ExecuteNonQuery();
iIDTransation = Convert.ToInt32(oParam2.Value);

But i have always the same error
 
Stored Procedure '' not found
 
Thanks for you help