't:Items' => {
  't:CalendarItem' => {
  't:Subject' => 'test',
  't:Sensitivity' => 'Normal',
  't:ExtendedProperty' => {
  't:ExtendedFieldURI' => {
     'PropertyType' => 'String',
     'PropertyName' => 'event_id',
     'PropertySetId' => 'c11ff724....'
  },
  't:Value' => '133113'
  },
  't:End' => '2012-04-26T08:00:00Z',
  't:ItemId' => {
  'Id' => 'AAAYAFNjb3....',
  'ChangeKey' => 'DwAAAB......'
  },
  't:LegacyFreeBusyStatus' => 'Free',
  't:Location' => {},
  't:IsAllDayEvent' => 'false',
  't:Start' => '2012-04-26T07:00:00Z'
  }}

##</code><code>##

$subject = $response_xml->{'soap:Body'}->{'m:FindItemResponse'}->{'m:ResponseMessages'}->{'m:FindItemResponseMessage'}->{'m:RootFolder'}->{'t:Items'}->{'t:CalendarItem'}->{'t:Subject'} ;