(function ($) {
    $.fn.selectChain = function (options) {
        var defaults = {
            key: "id",
            value: "label",
            data: {}
        };
        
        var settings = $.extend({}, defaults, options);
        
        if (!(settings.target instanceof $)) settings.target = $(settings.target);
        
        return this.each(function () {
            var $$ = $(this);

            $$.change(function () {
                var data = null;

                if (typeof settings.data == 'string') {
                	data = settings.data + '&' + this.name + '=' + $$.val();
                } else if (typeof settings.data == 'object') {
                    data = settings.data;
                   	data[this.name] = $$.val();
                }

 				if(typeof settings.data['add'] != 'undefined')
 				{
 					data[$(settings.data['add']).parent('select:first').attr('name')] = $(settings.data['add']).val(); 
 				}		               
                settings.target.empty();
                
                $.ajax({
                    url: settings.url,
                    data: data,
                    type: (settings.type || 'get'),
                    success: function (j) {
			if(settings.data.return_json)
			{
				try{
                    			j = eval('(' + j + ')');
 				}
                    		catch(err) { };
                    	}

                        var options = [], i = 0, o = null;

                        if(typeof j == 'object')
                        {
	                        for (i = 0; i < j.length; i++) {
	                            // required to get around IE bug (http://support.microsoft.com/?scid=kb%3Ben-us%3B276228)
	                            o = document.createElement("OPTION");
	                            o.value = typeof j[i] == 'object' ? j[i][settings.key] : j[i];
	                            o.text = typeof j[i] == 'object' ? j[i][settings.value] : j[i];
	                            settings.target.get(0).options[i] = o;
	                        }
	
	                        // hand control back to browser for a moment
	                        setTimeout(function () {
	                            settings.target
	                                                  .find('option:first')
	                                                  .attr('selected', 'selected')
	                                                  .parent('select')
	                                                  .trigger('change');
	                           
	                        }, 0);
	                    }
	                    else
	                    {
	                    	settings.target.html(j);	
	                    }

                    },
                    error: function (xhr, desc, er) {
                        // add whatever debug you want here.
                        alert("an error occurred");
                    }
                });
            });
        });
    };
})(jQuery);