You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am George Williams.

ASSISTANT: How may I help you today?

USER: I want to change my existing reservation. can you help me with that?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait for a minute.

USER: Sure.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: Ok, No issues, thanks for the information.

ASSISTANT: Thank you for reaching us.