You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you?

USER: I need to change my existing reservation as my plan to go for shopping at Boston got postponed. Can you help me i changing the reservation made on name Gary Allen?

ASSISTANT: Sure, I will help you to change your reservation. Please wait for a moment, while I check for the reservation.

USER: Ok.

ASSISTANT: Thanks for waiting, sorry there is no reservation found on your name in your system data.

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

ASSISTANT: Thank you for reaching us, we hope see you again.