$("#MyForm").live('submit',function(){
	var params = $(this).serialize();
	var self = this;
	
	$.ajax({
		type: 'POST',
		url: self.action,
		data: params,
		beforeSend: function(){
			alert('Closing');
			$.fancybox.close();
		},
		success: function(data){
			alert('Finished processing form');
			return false;							
		},
		dataType: 'json'
	});
	
	return false;
});
}

http://www.dropthenerd.com/close-fancybox-on-form-submit-but-before-processing-via-ajax/

Close a fancybox ON form submit and BEFORE processing with ajax.

ajax, post, jquery

jQuery