You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Timothy Lopez.

ASSISTANT: How can I help you?

USER: I would like to change my existing reservation, can you help me in changing my reservation?

ASSISTANT: Timothy Lopez, I am willing to help you for this. Let me check your reservation status in our records?

USER: Thank you. I will wait for your response.

ASSISTANT: Sorry for inconvenience, no reservation is found with your criteria.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you veru much for approaching us.