<Url type="text/html" method="GET" template="http://www.google.com/search">
  <Param name="q" value="{searchTerms}"/>
  <Param name="ie" value="utf-8"/>
  <Param name="oe" value="utf-8"/>
  <Param name="aq" value="t"/>
  <!-- Dynamic parameters -->
  <Param name="rls" value="{moz:distributionID}:{moz:locale}:{moz:official}"/>
  <MozParam name="client" condition="defaultEngine" trueValue="firefox-a" falseValue="firefox"/>
</Url>