WFS - modification

<wfs:Transaction service="WFS" version="1.0.0"
  xmlns:topp="http://www.openplans.org/topp"
  xmlns:ogc="http://www.opengis.net/ogc"
  xmlns:wfs="http://www.opengis.net/wfs">
  <wfs:Update typeName="topp:bc_roads">
    <wfs:Property>
      <wfs:Name>LENGTH</wfs:Name>
      <wfs:Value>3.14159</wfs:Value>
    </wfs:Property>
    <ogc:Filter>
      <ogc:FeatureId fid="bc_roads.1"/>
    </ogc:Filter>
  </wfs:Update>
</wfs:Transaction>