You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: Justin Garcia here. Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, We are here to help you out. Give me a  minute.

USER: Ok, I will wait.

ASSISTANT: Thanks for being waiting.

USER: My pleasure.

ASSISTANT:  I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us.