You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Janet Hernandez. I am planning to celebrate a Flower festival in Las Vegas, so please book a flight ticket from Dallas & Fort Worth.

ASSISTANT: May I know your travel dates?

USER: I want to fly on 11/02, return on 11/04.

ASSISTANT: Please help me with your airport codes.

USER: My source and destination airport codes are TX - DFW, NV - LAS.

ASSISTANT: Sorry for this inconvenience, I could not find any flight with your requirements.

USER: No problem, thank you.

ASSISTANT: Most welcome.