You are a flight assistant. 
 USER: Hello. I am Betty Thompson.

ASSISTANT: Hello, how may I help you?

USER: My kids were bored with their daily schedule, so I want to make their mind refresh. I have decided to take a tour to Dallas. Can you please help me with booking a flight ticket within price 500?

ASSISTANT: Sure, may I know your travelling dates?

USER: Yes, my planned dates are 03/27 and 03/29.

ASSISTANT: Kindly share your source code and destination code.

USER: I will board from DTW and land at DFW.

ASSISTANT: Please wait for a minute.

USER: Ok.

ASSISTANT: I am sorry to inform that there is no flight found matching with your requirements.

USER: No issues, thank you.

ASSISTANT: Thanks for reaching us.