Best way to do that job is to use the code:

var cropper = new Cropper(document.getElementById('img'), {
autoCrop: true,
autoCropArea: 1,
aspectRatio: 500 / 660,
minCropBoxWidth: 500,
minCropBoxHeight: 660,
viewMode: 2

});

Paste and place it in first line, then hit compile.