You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: As I am chef, I want to attend the food festival at Denver, DEN on 09/25. Could you help me to make a reservation with the name of Benjamin Campbell?

ASSISTANT: Sure,May I know the source code?

USER: Source code is San Francisco, SFO.

ASSISTANT: Please help me with your travel dates.

USER: My return date is on 09/27.

ASSISTANT: Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Not a issue, I will go with another airline. Thank you for your response.

ASSISTANT: Thank you for opting us.