I have flagged questions for moderator attention to delete them, but still I didn't get any response. Even my friend has old ID then me on stackoverflow and the same thing happen to him. So is there any time limit to delete the question if not then moderator should have to response for that?
If you visit your Flagging Summary* you can find a list of the dispositions for your flags and whether or not they were deemed valid, invalid, disputed, or if they are awaiting review.
* You can get to your flagging summary page by clicking on your user name, then clicking on your flag weight.