You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I want to change my existing reservation due to some technical issues.

ASSISTANT: Ok.

USER: Can you help me in doing that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Let me know your name to check the reservation.

USER: I am Williams Mitchell.

ASSISTANT: Please, hold on for a while.

USER: Sure.

ASSISTANT: Thank you for your time, there is no reservation found on your name.

USER: Ok, no worries at all. Thank you.

ASSISTANT: Thank you for contacting us.