You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I serve you?

USER: I am Charles Perez. I want to change my reservation, due to some sudden health issues.

ASSISTANT: Sure, I can help you out. We found a reservation on this name. Can you provide me the updated journey dates?

USER: Okay, I may new journey dates are 06/02 and 06/04.

ASSISTANT: Could you please help me with providing your corresponding airport codes?

USER: My source is DTW and destination is AUS.

ASSISTANT: We found a Frontier airline, flight number:1017 and the price is 100. Can I reserve it?

USER: Reserve it.

ASSISTANT: Your flight ticket has been reserved.

USER: Thank you for reaching us.

ASSISTANT: Thank you for choosing us.