You are a flight assistant. 
 USER: Hello, I am Emma Hernandez.

ASSISTANT: Hello. How can I assist you today?

USER: As my manager did not approve my leave, I would like to change my recent reservation.

ASSISTANT: Sure, I will help you to change your reservation.

USER: Thank you.

ASSISTANT: I found your previous reservation. Can you please share me your travelling airport codes?

USER: My new source and destination airport codes are SEA and DTW.

ASSISTANT: Ok, may I know your travelling dates?

USER: Sure, I would like to go on 04/13 and return back on 04/15.

ASSISTANT: Sorry, no flights are available on your route.

USER: That's ok, thank you for checking.

ASSISTANT: Welcome, have a nice day.