You're welcome.别客气。

Not at all.没什么。

Don't mention it.不必谢。

It was a real pleasure for me to do it.我很乐意这样做。

No trouble at all.一点儿也不麻烦。

Glad to have been of help.我很高兴能给您帮个大忙。

There is nothing to thank me for.没有什么可谢我的。