Slidebox currentIndex

I use a slidebox and ng-repeat

        <ion-slide-box  on-slide-changed="slideChanged(index)" 
                       show-pager="false">
          <ion-slide ng-repeat="new in cnews" disable-scroll="false">

every new has ID {{new.id}}, how to get it on current id on slide change and how to set to open a slide by id )
sorry for my english