select SUM in Cake

When I tried using follow code to get the sum of the column named

$conditions = array('fields'=>array('SUM( as servicecount'),'conditions'=>array('time_id BETWEEN ? AND ?'=>array($startid,$endtid)));
$services = $this->Serviceinfo->find('all',$conditions);

I had to fetch the sum data with services[0][0]['servicecount'] which seems a little weird.And What I expect is services['Serviceinfo']['servicecount'],or more simple one.Then how can I fix this?Thanks in advance!