向数据库表中提交信息无法实现，程序既不报错也不提交执行。代码如下：
string ConnString = System.Configuration.ConfigurationSettings.AppSettings["case"];
            //从<AppSettings>节读取连接字符串     
            SqlConnection sqlcon = new SqlConnection(ConnString);//创建SqlConnection对象
            sqlcon.Open();
                SqlCommand defendbase = new SqlCommand();
                 into Defend_information values (@Num_regist,@Defend_status_parties,@Defend_type,@Defend_name_parties,@Defend_add_parties,@Defend_postal_code,@Defend_phone)";
                defendbase.Parameters.Add("@Num_regist",Num_registTextBox.Text.ToString());
                defendbase.Parameters.Add("@Defend_status_parties",this.StatusDropDownList.SelectedItem.Value);
                defendbase.Parameters.Add("@Defend_type",this.TypeDropDownList.SelectedItem.Value);
                defendbase.Parameters.Add("@Defend_name_parties",Name_partiesTextBox.Text.ToString());
                defendbase.Parameters.Add("@Defend_add_parties",Add_partiesTextBox.Text.ToString());
                defendbase.Parameters.Add("@Defend_postal_code",Postal_codeTextBox.Text.ToString());
                defendbase.Parameters.Add("@Defend_phone",PhoneTextBox.Text.ToString());
                defendbase.Connection = sqlcon;
                defendbase.ExecuteNonQuery();
                Response.Write("<script>alert('提交成功！')</script>");
请大家帮忙！