;(function($) {

$.extend({
	
	bgchanger: function(options) {
		options = $.extend({}, $.BackgroundLoader.defaults, options);
		
		new $.BackgroundLoader(options);
		return this;
	}
	
});

$.BackgroundLoader = function (options) {
	
	var json;
	var currentIndex = 0;
	
	
	$.getJSON(options.url, function (data) {
	
		json = data.backgrounds;
		load();
	});
	
	function load() {
		var filename = $(json[ currentIndex ]).attr('imagefilename');
		if (!filename) {
			currentIndex++;
			load();
			return;
		}
		var url = options.imageUrlBase + '/background/' + filename;
		var img = new Image();
		img.onload = function () {
			if (currentIndex < $(json).size() - 1) {
				currentIndex++;
				load();
			}
		}
		img.src = url;
	}
}

$.BackgroundLoader.defaults = {
	url: '',
	imageUrlBase: ''
};

})(jQuery);