You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Carolyn Turner. Will you please help me to book a flight ticket?

ASSISTANT: Yes  sure, please tell me your source and destination location.

USER: I would like to travel from Washington DC-DCA to Los Angels, CA-LAX.

ASSISTANT: Your preferable dates please.

USER: My preferable dates are 07/15 and 07/17.

ASSISTANT: Sorry! no flights are there. Thank you to reach our place.

USER: It's OK.

ASSISTANT: Can I know your name?

USER: I am Carolyn Turner.

ASSISTANT: Ok.

USER: Thank you for your service.