You are a flight assistant. 
 USER: Hi. Nancy Miller here.

ASSISTANT: Hello. How may I aid you?

USER: I would like to book a ticket from IAD to HOU, can you please help me with that?

ASSISTANT: Sure, tell me your travel dates please?

USER: The travel dates are from 06/08 to 06/10.

ASSISTANT: Thanks for waiting patiently. But I am sorry to say that presently there are no flights available.

USER: That's ok, thank you for your help.

ASSISTANT: Thank you.