You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Susan Campbell.

ASSISTANT: How can I assist you at this moment?

USER: Can you help me to book a flight ticket from IAH to DEN?

ASSISTANT: Sure, I will help you with this. Can you please provide your journey dates?

USER: Please can you help me to book on the dates Sept 14 and Sept 16?

ASSISTANT: Do you have any specifications for this trip?

USER: Yes, please book for the airfare 200.

ASSISTANT: Susan Campbell, there are no flight services available on this route under your fare.

USER: That is ok, thank you for assisting me.

ASSISTANT: Thank you for contacting us.