You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Sarah Evans want to visit Houston, can you book a ticket from BOS to HOU?

ASSISTANT: Sure, can you please tell your travelling dates?

USER: Sure, my travelling dates will be 01/22 and 01/24.

ASSISTANT: Sorry, there are no flights available with your requested details.

USER: That's ok, thank you.