You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I am Pamela Walker. Can you please book a flight ticket from SFO to IAH?

ASSISTANT: Sure, I am happy to help you with that. Can I have your itinerary dates?

USER: Sure, I need to travel on dates  of 12/19 and 12/21.

ASSISTANT: Ok, please wait for a minute.

USER: Sure, take your time.

ASSISTANT: Sorry to say that, there are no flight's available based on your travelling dates.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Thank you for consulting us.

USER: Most welcome.