value.item_attr = UF_STYLER_VALUE;
value.item_id = EX_SELECTION_2;
/* UF_STYLER_INTEGER_VALUE is to get selected index; if you want to get the selected string value, use UF_STYLER_STRING_VALUE instead. */
value.indicator = UF_STYLER_INTEGER_VALUE;
UF_STYLER_ask_value( dialog_id, [$value )]