You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Jerry Martin here. I need to reserve a ticker from DCA to OAK, can you help me in doing that?

ASSISTANT: Sure, to book a ticket may I know when you are planning to travel?

USER: My trip dates are Feb 13 to 15.

ASSISTANT: Do you need any connection limit?

USER: I need a connection limit.

ASSISTANT: Is there any airline preference for you?

USER: I need normal-cost airline.

ASSISTANT: Please provide your specifications.

USER: My return time must be in evening.

ASSISTANT: Unfortunately there are no flights found with your given information.

USER: Ok, no issues.

ASSISTANT: Thank you for reaching us.

USER: Thank you for the information.