You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I serve you?

USER: Can you please book a flight ticket for me?

ASSISTANT: Sure, Can you please provide me with your journey details?

USER: My journey details are  from Denver,CO-DEN to Charlotte,NC-CLT. My travelling  dates are Aug 21 and return on Aug 23. Can you please check whether the flight is available or not?

ASSISTANT: OK, Give me a minute I will check the availability and let you know.

USER: OK.

ASSISTANT: Thanks for your patience.

USER: It's OK.

ASSISTANT: We are sorry to say this we did not find any flights as per your requirements. May I know your name please?

USER: Thank you. I am Amy collins.

ASSISTANT: Thank you have a nice day.

USER: Wish you the same.