Combobox 변경시

comboboxA.on("change", function(cb, newValue, oldValue){

    if(newValue == "USA"){
       comboboxB.store.loadData(["Texas", "New York", "Washington"]);
       comboboxB.setValue("Texas");
    }
    else if(newValue == "England"){
       comboboxB.store.loadData(["London", "Manchester"]);
       comboboxB.setValue("London");
    }

});