You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: : Due to some health issue I need to change my reservation, can you please help me in that?

ASSISTANT: Sure. May I know your name?

USER: I am Melissa Davis.

ASSISTANT: We didnt found any reservation by this name.

USER: Ok, may be I did not reserve it properly. Thank you.

ASSISTANT: Thank you for consulting us.