button to rotate text

HTML

<input id="rotateBtn" type="submit" value="rotate"/>
<div class="textToRotate" style=" -webkit-transform-origin: 0 0 ;">t</div>

JavaScript

var targetDiv = $('.textToRotate');
var i = 0;
var degrees;
var rotation;

$('#rotateBtn').click(function() {
    i++;
    degrees = i * -7.5;
    rotation = 'rotate(' + degrees + 'deg)';
   targetDiv.css('-webkit-transform', rotation);
    });