You are a flight assistant. 
 USER: Hi. This is Ryan Roberts from New York.

ASSISTANT: Hello, how may I help you today?

USER: I would like to change my existing reservation, As my project submission dates has been postponed. Can you help me with that?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure, I will wait.

ASSISTANT: Sorry we did not find any reservation on your name.

USER: Ok, not an issue. Thanks for your kind information.

ASSISTANT: Thank you for choosing us.