System.IndexOutOfRangeException:

I want to output the value of COUNT(ContractorLinkInfo.CG_ID) AS CatCount:  I am getting the following error:

An SqlParameter with ParameterName '@CatCount' is not contained by this SqlParameterCollection.
Exception Details: System.IndexOutOfRangeException: An SqlParameter with ParameterName '@CatCount' is not contained by this SqlParameterCollection.
Source Error:




Line 116: cmd.Parameters.AddWithValue("@ELongDB", ELongDB);
Line 117: cmd.Parameters.AddWithValue("@WLongDB", WLongDB);
Line 118: cmd.Parameters["@CatCount"].Direction = ParameterDirection.Output;
Line 119: con.Open();
Line 120: SqlDataReader reader = cmd.ExecuteReader();

@NLatDB float,
@SLatDB float,
@ELongDB float,
@WLongDB float,
@CatCount int output
AS
SELECT    Contractors.CG_Name, COUNT(ContractorLinkInfo.CG_ID) AS CatCount, Contractors.BCG_ID
FROM      Contractors INNER JOIN
                      ContractorLinkInfo ON Contractors.BCG_ID = ContractorLinkInfo.CG_ID INNER JOIN
                      Zip2006 ON ContractorLinkInfo.Zip = Zip2006.ZIPCode
WHERE     (Zip2006.Latitude < @NLatDB ) AND (Zip2006.Latitude > @SLatDB ) AND
                      (Zip2006.Longitude < @ELongDB ) AND (Zip2006.Longitude > @WLongDB )
GROUP BY Contractors.CG_Name, ContractorLinkInfo.CG_ID, Contractors.BCG_ID
ORDER BY Contractors.CG_Name 
RETURN

protected void CheckCategoryCount()
    {
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString6"].ConnectionString);
        int CategoryCount = int.MaxValue;
        SqlCommand cmd = new SqlCommand("CategoryCount", con);
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.Parameters.AddWithValue("@NLatDB", NLatDB);
        cmd.Parameters.AddWithValue("@SLatDB", SLatDB);
        cmd.Parameters.AddWithValue("@ELongDB", ELongDB);
        cmd.Parameters.AddWithValue("@WLongDB", WLongDB);
        cmd.Parameters["@CatCount"].Direction = ParameterDirection.Output;
        con.Open();
        SqlDataReader reader = cmd.ExecuteReader();
        {
            if (reader.Read())
            { CategoryCount = (int)reader["CatCount"]; }
        }
        reader.Close();
        con.Close();

 

Thank you