FabricJS - Rotate Object via Variable Name on Button Click

Using a button click, rotate an object on the FabircJS Canvas that is specified by a variable.

HTML

<script src="https://rawgit.com/kangax/fabric.js/master/dist/fabric.js"></script>
<script src="http://promincproductions.com/gaTrackingJSFiddle.js"></script>
<button id="rotate">Rotate Image 15&deg;</button>
<canvas id="c" width="400" height="400"></canvas>

CSS

canvas{
  border-width: 1pz;
  border-style: solid;
  border-color: #000;
}

JavaScript

var canvas = new fabric.Canvas('c');

var src = "http://fabricjs.com/lib/pug.jpg";

var rotateThisImage;

fabric.Image.fromURL(src, function(oImg) {
    oImg.set({
        width: 200,
        height: 200,
        originX:  'left',
        originY: 'top'
    });
    canvas.add(oImg);
    canvas.centerObject(oImg);
    canvas.renderAll();
    rotateThisImage = oImg;
});

$("#rotate").click(function(){
       var curAngle = rotateThisImage.getAngle();
       rotateThisImage.setAngle(curAngle+90); 
       canvas.renderAll();
});