function add(event) {
	$(this).children('img:first').replaceWith('<img src="img/calendar_delete.png">');
	addToCalendar(this.id);
}

function remove(event) {
	$(this).children('img:first').replaceWith('<img src="img/calendar_add.png">');
	removeFromCalendar(this.id);
	if(removeSession) {
		$('tr.session_' + this.id).remove();
		window.location.reload();
	}
}

function addToCalendar(id) {
	$.getJSON('content/modifyPC.php', {action:'add', sId:id},
		function(data) {
			//alert("added " + data.aSId + " to the calendar");
		});
}

function removeFromCalendar(id) {
	$.getJSON('content/modifyPC.php', {action:'remove', sId:id},
		function(data) {
			//alert("removed " + data.aSId + " from the calendar");
		});
}