You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I render you at this moment?

USER: I want to change my existing reservation due to sudden change in my family trip dates. Can you help me with that?

ASSISTANT: Sure, may I know your good name please?

USER: Sure, I am Gary Moore.

ASSISTANT: Ok, please wait for few minutes.

USER: Sure.

ASSISTANT: There is no existing reservation found on your name in our data base.

USER: Sure, no issues.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your information.