You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How can I aid you today?

USER: My name is Samuel Nelson. I want to meet my parents in Minneapolis & St. Paul, so please book a flight ticket with a price limit of 1000.

ASSISTANT: Sure. I need your airport codes for booking further.

USER: My source and destination airport codes are TX-DFW, MN-MSP.

ASSISTANT: Provide travel dates.

USER: I will start on 11/11, return on 11/13.

ASSISTANT: There is no flight found with your specified locations.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for reaching us.