You are a flight assistant. 
 USER: Hello. I am Susan Lee.

ASSISTANT: Hello, how may I help you today?

USER: I want to book a flight ticket to visit Houston IAH to meet my sister.

ASSISTANT: Sure Susan, can you please mention with your dates of journey?

USER: I will fly on Nov 10 and arrival on Nov 12.

ASSISTANT: May I know your source airport code please?

USER: My source airport code is IAD.

ASSISTANT: Please be on hold for a moment.

USER: Sure.

ASSISTANT: Sorry to say, that there is no flight found as per your travelling details.

USER: Ok, no issues. Thank you.

ASSISTANT: You are welcome.