var zoomPage = function(page) {
            if (page.$child && page.naturalHeight && page.naturalWidth) {
                var scale = state.zoomlevel / 100;
                var shiftX = 0;
                var shiftY = (page.naturalHeight / 2) * ((state.zoomlevel - 100)/100);
                page.$el.css({
                    height: (page.naturalHeight * state.zoomlevel / 100) + 'px',
                    width: (page.naturalWidth * state.zoomlevel / 100) + 'px'
                });
                page.$child
                    .css('-webkit-transform', 'scale(' + scale + ')')
                    .css('-moz-transform', 'scale(' + scale + ')')
                    .css('-ms-transform', 'scale(' + scale + ')')
                    .css('transform', 'scale(' + scale + ')');
                page.$el
                    .css('-webkit-transform', 'translate(' + shiftX + 'px,' + shiftY + 'px)')
                    .css('-moz-transform', 'translate(' + shiftX + 'px,' + shiftY + 'px)')
                    .css('-ms-transform', 'translate(' + shiftX + 'px,' + shiftY + 'px)')
                    .css('transform', 'translate(' + shiftX + 'px,' + shiftY + 'px)');
            }
        }