You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Thomas Gonzalez.

ASSISTANT: How may I assist you?

USER: I have decided to change my reservation due to my planned event got postponed another dates. So please help me with that.

ASSISTANT: Sure, I am here to help you out.

USER: Thank you.

ASSISTANT:  Mary Martinez, we haven't found any reservation under your name in our database.

USER: Oh! It may not be booked properly due to some technical issues. Anyway, thank you for your time.

ASSISTANT: Thank you for reaching us.