$('#xxx').combobox({
	url: xxx,
	valueField: 'xx',
	textField: 'xxx',
	panelHeight: 'auto',
	width : 150,
	height : 20,
	editable: false,
	loadFilter: function(data){
                //此处data为数组，核心是数组的sort方法
		data.sort(function (a, b) {
			return a.xxxx>b.xxxx;
		})
		return data;
	},
	onShowPanel : function(){
		var count = $(this).combobox('getData').length;
		if(count > 10){
			$(this).combobox('panel').height(180);
		}else{
			$(this).combobox('panel').height("auto");
		}
	}
});