Ion-slide height

Hi all,
I tried to modify the slide’s heights but I had some problems…
So this is the slide

<ion-slide-box ...........>`
<ion-slide>`
<div class="box number">
<p>some text</p>
</div>
<div class="box alpha">
<p>another text</p>
</div></ion-slide></ion-slide-box>

in the CSS stylesheet I do different ways.
First way:

.box { height: 100% }

Second way

.number { height: 50px }
.alpha { height: 200px }

But the first and second way doesn’t work.
How can I fix it?
Thanks

HTML

JS

$scope.slideChanged = function (index) {
var height = $(".slide" + index).css(“height”);
$(’.slider’).css(“height”,height);
};

Hope it helps.