how to get data from data base as o/p paramter using stored procedure

 public int totalpaymentforth(string dt,string dt1,int theaterid,int st)
    {

        con.Open();
        cmd = new SqlCommand("SPTOTALAMOUNT", con);
        cmd.CommandType = CommandType.StoredProcedure;
        SqlParameter[] p1 = new SqlParameter[4];
        p1[0] = cmd.Parameters.Add("@DT", SqlDbType.NVarChar, 50);
        p1[0].Value = dt.ToString();

        p1[1] = cmd.Parameters.Add("@DT1", SqlDbType.NVarChar, 50);
        p1[1].Value = dt.ToString();

        p1[2] = cmd.Parameters.Add("@THEATERID", SqlDbType.Int, 4);
        p1[2].Value = theaterid.ToString();
        SqlParameter op = cmd.Parameters.Add("@TOTAL", SqlDbType.Int, 4);
        op.Direction = ParameterDirection.Output;
        cmd.ExecuteScalar();
        con.Close();
        return int.Parse(op.Value.ToString());

    }