You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,.

USER: I am Betty Collins.

ASSISTANT: How can I serve you today?

USER: I want to change my existing reservation. Can you help me in doing this?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please be on hold for a minute.

USER: Sure, I will wait.

ASSISTANT: Thanks for holding on, there is no reservation found on your name.

USER: Not a problem, thank you for your information.

ASSISTANT: Thanks for contacting us, hope to serve you again.