If parents want their children to be disciplined, they have to be disciplined when laying down rules too. Often a parent's first reaction may be to say no to something or to deny their child something, but after a child starts nagging, parents give in and relent. If you think you may relent later on, then don't say no. Say no only when you mean it. If you are undecided, then say 'maybe'. Remember that no should not mean maybe. Your child should learn that no means no, not just where your commands are concerned, but also as far as her own limits are concerned in the future, so when she says no, she will not easily be persuaded to change her mind.
Although you as a parent are the best judge as to what's right for your children, try and avoid giving your child a blank 'no' as a response for something he wants very badly. Of course you don't have to give him permission to do something you feel is not right for him, but always give explanations. Don't say "Because I said so." Every child will really want to know why he is being denied something, and you as a parent should tell him why you think it is wrong. So if your daughter wants to go to a particular party and you don't want to let her go, tell her exactly why you think it is not a good idea. Often the explanation "What will people say if they see you out late at night," is met with furious outbursts. Perhaps you too should analyse your reasoning and try and come up with some more plausible explanations. The party may be at a location that is a little too far, and you are not happy with the thought of her driving back all that distance at night. Lay down a set of rules for your child. Don't give her one excuse one time, another excuse another time. Keep one standard deadline for your child.
If you do let her go out at night, then make sure she comes back before your deadline. If she doesn't, then you can punish her by grounding her for a week or so, depending on how late she is. And don't give her a punishment that you will not abide by, because she will not take your deadlines seriously. So grounding her for a month and then letting her out after a week does not make sense. If you want her to be disciplined, you have to be disciplined too.
There may be times when you don't want her to go to parties with a certain set of people. Make sure she knows this. Let her know that she will be allowed to go with certain friends, and will not be allowed to go with certain others.
If you don't want her to go out for parties at all, tell her that you will start giving her permission after the age of 18 or 21, to certain select parties, and until then she will not be allowed. You can then compensate by letting her go for movies, lunches and dinners with friends. If you let her go because she persists, then it will be even more difficult to stop her the next time - that is, if you feel that you want to stop her.