You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: My name is Timothy Lopez.

ASSISTANT: Yes, Timothy.

USER: I want to extend my travelling dates. So, can you please help me in changing my existing reservation?

ASSISTANT: Sure, please wait a moment, let me check.

USER: Ok.

ASSISTANT: Sorry for inconvenience, no reservation found.

USER: It's Ok. Thank you for the information.

ASSISTANT: Thank you for reaching us.