You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,.

USER: I am Catherine Collins.

ASSISTANT: How can I render you today?

USER: Can you please help me in changing my reservation?

ASSISTANT: Sure, we are glad to aid you.

USER: Thank you.

ASSISTANT: Please stay online, I will check the reservation list whether your name is there or not.

USER: Ok.

ASSISTANT: Thanks for your precious time. Sorry, we could not find any reservation is our batabase.

USER: It's ok, thank you for your information.

ASSISTANT: Thank you for availing us.