You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, can you please tell me how can I guide you?

USER: I'm Mark Walker, planning to visit Houston city, can you please book me a ticket from JFK to IAH?

ASSISTANT: Ok, may I know your travel dates?

USER: My preferable journey dates are from 06/30 to 07/02.

ASSISTANT: Sorry, no flights found.

USER: Ok, not an issue. Thank you for providing information.

ASSISTANT: Thank you for reaching us.

USER: Welcome.