1 Question: I want to ask about talking to ones fiancee on telephone, is it permissible or not?
Answer: If there is no such a fear that you might fall into a sin, there would be no problem.
2 Question: Is it permissible to chat with girls on the internet?
Answer: If there is a fear that a girl or a boy may be drawn towards sin, it is not permissible. Normally chatting ends up in a sin for both sides.
3 Question: Is it permissible for a boy of fifteen years to have a girl friend?
Answer: Friendship with a non-mahram is not allowed.