You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. May I know what kind of service you are looking for?

USER: As, my manager didn't approved my leave, I want to change my reservation. Can you help me with that?

ASSISTANT: Sure, I can change your reservation right now. Before that I need to know your good name please?

USER: Melissa Miller here.

ASSISTANT: Ok, Please allow me a moment to check for the previous reservation in our database.

USER: Sure, I will wait for your response.

ASSISTANT: Thanks for remaining so positive, We are sorry to say that there is no active reservation found on your name.

USER: Ok, something went wrong at the time of booking. Anyways, thanks for the information.

ASSISTANT: Thanks for reaching us, wish you a nice day.