<span onMouseOver="show_agenda_details({{agenda.id}}, {{slot.id}});" onMouseOut="hide_agenda_details({{agenda.id}}, {{slot.id}});">
        {% if attendee in agenda.meeting.attendees %}
            <img class="icon" src="/media/img/attending.png" alt="Attending">
        {% else %}
            <img class="icon" src="/media/img/not_attending.png" alt="Not Attending" onclick="changeStatus('{% url summit.schedule.views.attend_meeting agenda.meeting.summit.name agenda.meeting.id %}', 'img_{{agenda.meeting_id}}') id="img_{{agenda.meeting_id}}">
        {% endif %}


code code code more code
some more fun over here

blah blah blah scripts

<script>
function changeStatus(attend_url, img_tag_id)
{
$.post(attend_url, { participation: "ATTENDING" } , function(data){ document.getElementById(img_tag_id).setAttribute("src","/media/img/attending.png"); });
}
</script>