change label system_id

[mariano]

I have create a class Regla
with this code

<class id="Regla" _delta="define">
      <parent>SoftwareInstance</parent>
      <properties>
        <category>bizmodel,searchable</category>
        <abstract>false</abstract>
        <key_type>autoincrement</key_type>
        <db_table>regla</db_table>
        <db_key_field>id</db_key_field>
        <db_final_class_field/>
        <naming>
          <attributes>
            <attribute id="name"/>
            <attribute id="system_name"/>
          </attributes>
        </naming>
        <display_template/>
        <icon>images/regla.png</icon>
        <reconciliation>
          <attributes>
            <attribute id="name"/>
            <attribute id="org_id"/>
            <attribute id="organization_name"/>
            <attribute id="system_id"/>
            <attribute id="system_name"/>
          </attributes>
        </reconciliation>
      </properties>
      <fields>
        <field id="NroRegla" xsi:type="AttributeString">
          <sql>NroRegla</sql>
          <default_value/>
         </field> 
            <field id="TicketEscalado" xsi:type="AttributeString">
          <sql>TicketEscalado</sql>
          <default_value/>
          <is_null_allowed>true</is_null_allowed>
        </field> 
            <field id="Puerto" xsi:type="AttributeInteger">
          <sql>Puerto</sql>
          <default_value/>
          <is_null_allowed>true</is_null_allowed>
        </field>
        <field id="FechaInicio" xsi:type="AttributeDate">
          <sql>FechaInicio</sql>
          <default_value/>
          <is_null_allowed>true</is_null_allowed>
        </field>    
            <field id="FechaFin" xsi:type="AttributeDate">
          <sql>FechaFin</sql>
          <default_value/>
          <is_null_allowed>true</is_null_allowed>
        </field> 
      </fields>
      <presentation>
        <details>
          <items>
            <item id="name">
              <rank>10</rank>
            </item>
            <item id="org_id">
              <rank>20</rank>
            </item>
            <item id="status">
              <rank>30</rank>
            </item>
            <item id="business_criticity">
              <rank>40</rank>
            </item>
            <item id="system_id">
              <rank>50</rank>
            </item>
           <item id="NroRegla">
              <rank>60</rank>
            </item>   
            <item id="Puerto">
              <rank>70</rank>
            </item>   
            <item id="FechaInicio">
              <rank>80</rank>
            </item>   
            <item   id="FechaFin">
              <rank>90</rank>
            </item>   
            <item id="description">
              <rank>100</rank>
            </item>
            <item id="contacts_list">
              <rank>110</rank>
            </item>
            <item id="services_list">
              <rank>170</rank>
            </item>
          </items>
        </details>
        <search>
          <items>
            <item id="name">
              <rank>10</rank>
            </item>
            <item id="org_id">
              <rank>20</rank>
            </item>
            <item id="business_criticity">
              <rank>30</rank>
            </item>
             <item id="system_id">
              <rank>50</rank>
            </item>         
           <item id="NroRegla">
              <rank>60</rank>
            </item>   
            <item id="Puerto">
              <rank>70</rank>
            </item>   
            <item id="FechaInicio">
              <rank>80</rank>
            </item>
            <item   id="FechaFin">
              <rank>90</rank>
            </item>
          </items>
        </search>
        <list>
          <items>
            <item id="org_id">
              <rank>10</rank>
            </item>
            <item id="business_criticity">
              <rank>20</rank>
            </item>
            <item id="system_id">
              <rank>30</rank>
            </item>
            <item id="software_id">
              <rank>40</rank>
            </item>     
           <item id="NroRegla">
              <rank>60</rank>
            </item>   
            <item id="Puerto">
              <rank>70</rank>
            </item>   
            <item id="FechaInicio">
              <rank>80</rank>
            </item>   

            <item   id="FechaFin">
              <rank>90</rank>
            </item>   
          </items>
        </list>
      </presentation>
      <methods>
        <method id="GetRelationQueries">
          <comment>/**
     * Placeholder for backward compatibility (iTop &lt;= 2.1.0)
     * in case an extension attempts to redefine this function...    
     */</comment>
          <static>true</static>
          <access>public</access>
          <type>Overload-DBObject</type>
          <code><![CDATA[   public static function GetRelationQueries($sRelCode){return parent::GetRelationQueries($sRelCode);} ]]></code>
        </method>
      </methods>
       </class>

In dictionary can change label puerto but i cant change system_id

why?How can do?

[Pierre Goiffon]

Hello,
You can't override in a child class a field defined in the hierarchy above :/