Dear Xiaohong,
Glad to receive your letter.Through your letter,I know that you have some problems wih your friend.Some times ago I also had the same trouble to you.At that time,I had a joke with my friend,but she treated it seriously and she was angry with me.We hadn't talk with each other for a long time.however,I didn't want to give up our friendship,so I explained to her and got her understanding.Now we are going on very well.
Anyhow,freiship is cherish.You can find a good chance to chat with your friend and tell her that you were just joking and then get her forgiveness.I hope you and your friend will get better soon.
Yours
Faithfully
XiaoMing