You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Timothy Lewis.

ASSISTANT: How may I help you out?

USER: Due to urgent meeting, I am going to change my existing reservation. Can you please help me for this?

ASSISTANT: Sure, I will help you in changing the ticket.

USER: Ok, I will wait for your kind response.

ASSISTANT: Sorry, there are no reservations found.

USER: Not a big issue, thank you very much for your kind information.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.