You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I am planning to change my travelling dates, so can you help me to change my reservation?

ASSISTANT: Sure, I am here to help you. Can you please help me with your name?

USER: My name is Gary Green.

ASSISTANT: Please wait for a mean while.

USER: Sure.

ASSISTANT: Sorry Green, there is no reservation found under your name to change your reservation.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: You are welcome.