How to change src (ajax ref in options (events: 'href') when calling refetchEvents

My site is for listing theatrical productions

(http://theaterOnline.com)

I want to use a drop down list to enable users to filter the listings by location or genre.

The following code refreshes the screen:

$("#cfilter").change(function() { 
    $('#calendar').fullCalendar('refetchEven开发者_StackOverflow中文版ts')
})

but I need to be able to change SRC in the ajax call below:

$.ajax({
    url: src,
    dataType: 'json',
    data: params,
    cache: options.cacheParam || false, 
    success: reportEventsAndPop
})

which is a passed parameter from eventSources[1]

TIA for anyone who can help!

best just to use a custom function with custom code that does the ajax request: http://arshaw.com/fullcalendar/docs/event_data/events_function/

(of course use json, not xml like in the example)