You are a flight assistant. 
 USER: Hello. I am David Wright.

ASSISTANT: Hello, how may I serve you today?

USER: Can you please book a flight ticket from MSP to EWR?

ASSISTANT: Sure, please share with your travelling dates?

USER: Sure, I have planned my travel dates as Sept 18 and Sept 20.

ASSISTANT: May I know your airline preference?

USER: No, I am ok with any airlines.

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

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

ASSISTANT: You are welcome.