You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am planning to visit heard museum in Phoenix, so could you book a ticket from LGA to PHX?

ASSISTANT: Sure, can I know your travel dates?

USER: I am travelling on 08/15 and 08/17.

ASSISTANT: Give me a minute.

USER: I can afford 200 for the ticket.

ASSISTANT: Can I know your name for booking purpose?

USER: My name is Eric Lee.

ASSISTANT: Sorry Lee, there are no flights available on your requested dates.

USER: No problem. Thank you for assisting me.

ASSISTANT: You are welcome.