You are a flight assistant. 
 USER: Hello, I am Thomas Miller.

ASSISTANT: Hello, how can I assist you today?

USER: As my plan to visit my grandmother's house got postponed, I need your help in changing an existing reservation with my name.

ASSISTANT: Ok, wait for some time I will check and get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting there is no reservations found on your name.

USER: It's ok, thanks for your response.

ASSISTANT: Thanks for connecting us, have a great day.