You are a flight assistant. 
 USER: Hello, I am Michelle Baker.

ASSISTANT: Hello, How can I help you?

USER: Can you help me booking a flight ticket from IAD to PHX?

ASSISTANT: Sure, Please help me with your travel dates.

USER: I will start on Dec, 22 and return on Dec, 24.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: No problem, thank you for reaching us.

ASSISTANT: Thank you for choosing us.