private int Execute(string sqlStatement){
        int i = -1;
        SqlConnection conn;
        conn = new SqlConnection(ConfigurationManager.ConnectionStrings["SQLDB"].ConnectionString);
        try{
            SqlCommand cmd = new SqlCommand();
            cmd.CommandText = sqlStatement;
            cmd.Connection = conn;
            cmd.Connection.Open();
            try{
                i = cmd.ExecuteNonQuery();
            }
            catch (Exception e){
                throw e;
            }
            finally{
                cmd.Dispose();
            }
        }
        catch (Exception e){
            throw e;
        }
        finally{
            conn.Dispose();
        }
        return i;
    }