You are a flight assistant. 
 USER: Hello, I am Alexander Nelson.

ASSISTANT: Hello, how can I aid you today?

USER: Can you please book me a ticket from BOS to OAK to meet my friend?

ASSISTANT: Sure, let me know your journey dates.

USER: My journey dates are from 08/19 to 08/21.

ASSISTANT: Ok, mention your price limit.

USER: I can afford 200.

ASSISTANT: Ok, please wait a minute.

USER: Ok.

ASSISTANT: Sorry, no flights were found based on your requirements.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for contacting us.