You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, How Can I serve you?

USER: I need to travel to Oakland, CA-OAK to attend my friends wedding, Can you help me to make my reservation from Washington, DC-IAD?

ASSISTANT: Sure, May I know the travelling dates?

USER: I will start from Washington on 07/14, will be returning on 07/16.

ASSISTANT: Ok, wait a minute. Thanks for waiting. Unfortunately, there are no flights matches to your requirements.

USER: Ok, Thank you.

ASSISTANT: May I know your name?

USER: By the way I am Elizabeth Brown.

ASSISTANT: Ok, thanks for choosing us.