You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Charles Allen.

ASSISTANT: What help that I can do for you?

USER: I need to amend my reservation, can you help me out please?

ASSISTANT: Sure, please give me a moment.

USER: Sure, take your own time.

ASSISTANT: I am unable to find any previous ticket booking done on the name which you have provided.

USER: That's ok, no problem. Anyway thank you for your help.

ASSISTANT: You are most welcome and have a nice day.