Change font size with slider

So I'm trying to change a label's font size using a slider. Both the slider and the text appear but moving the slider doesn't cause a change. Some help please

.xml

<Alloy>
    <Window id='articleWindow' backgroundColor="white">
 
        <Slider id='slider' onChange='onChange'/>
        <Label id="story"/>
 
    </Window>
</Alloy>

"#slider": {
    top: 5,
    min: 0,
    max: 100,
    value: 50,  
},
"#story": {
    color: 'black',
    font: {fontFamily:'Arial', fontSize: 15},
    top:10,
    left:10,
    right:10,
}

$.story.text = "I love Cheese"
 
$.slider.text = $.slider.value;
function onChange (e){
    $.story.font.fontSize = String.format("%3.1f", e.value);;
    Ti.API.info($.story.font.fontSize);
 
};