I am trying to display an image in the `fc-event-inner` class using `addClass`. I want to do this with `jquery` so I can use different images in different events. Can anyone tell me why this doesn't work?

```
calendar.fullCalendar('renderEvent', {
    title: title,
    start: start,
    end: end,
    allDay: allDay,
    eventRender: function(copiedEventObject,element) {                                          
        element.find('.fc-event-inner').css('background-image',"url(icons/kalender_medicin_100px.png)")
    },
    className: '.fc-event-inner'
});

```