You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Linda Thompson.

ASSISTANT: How may I help you?

USER: I want to book a flight ticket within 200. Can you help me?

ASSISTANT: Linda Thompson, may I know your travelling dates?

USER: 07/08 and 07/10 are my travelling dates.

ASSISTANT: What are your desired airport codes?

USER: OAK and LGA are my airport codes.

ASSISTANT: Sorry to inform you, there are no flights available for your journey.

USER: No issue. Thank you.

ASSISTANT: Thank you for choosing us. Have a nice day.