Updating the ExtendedAttributes for a calendar event

As mentioned in the Extended Attributes in REST link I posted above, use two underscores at the beginning of the field name.

I tried this, and it still didn't work:

	    	jQuery.telligent.evolution.put({
	            url: jQuery.telligent.evolution.site.getBaseUrl() + 'api.ashx/v2/calendars/events/{id}.json',
	            data: { 
		            'id': response.eventId,
                    __ExtendedAttributes_PostingStatus: context.status,
		            __ExtendedAttributes_PostingEndDate: "Test"  //t$(context.inputs.postingEndDate).val()

            	 },
	            success: function(response) {
                    alert('success'+response);
	            }
        });