Align ion-spinner in ion-slide-box

Hi, i have this ion-view on my application and I can’t center the ion-spinner on the screen orizontally and vertically.
Can anyone help me?
Thanks in advance.

 
                    <div ng-hide="slide.call == null" class=" list card">
                        
                        <div class="item">
                            <form-input name="callerCompany" type="text" ng-model="slide.call.calerCompany" label="Company"></form-input>
                            <form-input name="callerName" type="text" ng-model="slide.call.callerName" label="Name"></form-input>
                        </div>
                        <div class="item">
                            <form-input name="callerEmail" type="text" ng-model="slide.call.callerEmail" label="Email"></form-input>
                            <form-input name="callerPhone1" type="text" ng-model="slide.call.callerPhone1" label="Phone1"></form-input>
                            <form-input name="callerPhone2" type="text" ng-model="slide.call.callerPhone2" label="Phone2"></form-input>
                            <form-input name="callerFax" type="text" ng-model="slide.call.callerFax" label="Fax"></form-input>
                        </div>
                        </div>
                        <!-- SOLO PER DEBUG
                          id={{slide.call.callId}} nr={{slide.nr}}<br>
                          index {{$index}} / length {{slides.length}}<br>
                          selectedSlide={{selectedSlide}}<br>
                          thisSlideIndex={{thisSlideIndex}}-->
                    </div>
            </ion-slide>
        </ion-slide-box>
    </ion-content>
</form>