Before you do everything, smile first.
When you need some help, you should say: "Excuse me." At the same time,if you show your unhappy face, he will be unhappy too. How can you get the help while he has no pleasure7 So show your smile, and you will get his help.
In fact, smile is a difficult job. It seems very difficult for you to smile when you are sad. Don't be afraid. Make up your mind to try once, only once, and you will find that you are much better in heart.
Smile is also a kind of language which cannot be heard by anyone, but persons always know its meaning. When you meet your friends in the morning, smile means "Good morning ! "When you fail, the friend's smile means "Have another try !" So when you smile, although you don't say any word, you can understand:each other.
Remember to smile, and happy life you'll get, I think!