You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Amy Perez.

ASSISTANT: How can I help you?

USER: I am planning to visit San Francisco, can you please book me a ticket from IAH to SFO?

ASSISTANT: Sure, I will help you to book a flight ticket. Can you please share me your travelling dates?

USER: My preferable journey dates are from Oct 28 to Oct 30.

ASSISTANT: Please give me a moment.

USER: Please ensure that my depart flight time is in evening time.

ASSISTANT: Sorry, no flights are available on your route.

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

ASSISTANT: Welcome, have a nice day. Thank you for choosing us.