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

ASSISTANT: Hello, how may I aid you?

USER: I am planning to attend a Innovation festival at Las Vegas, so can you please book a ticket on 03/19 and return on 03/21?

ASSISTANT: Sure, Can you please provide your journey airport codes?

USER: My journey airport codes are from MN-MSP to NV-LAS.

ASSISTANT: Ok, May I know your price limit?

USER: My price limit is 500.

ASSISTANT: Ok, please wait for a while.

USER: Ok.

ASSISTANT: Thank you for your time, No flights were found with your given details.

USER: Not a problem, thank you.

ASSISTANT: Thank you for choosing us.