You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Amy Thompson.

ASSISTANT: How can I assist you?

USER: I need to change my existing reservation due to postpone of my event at Houston.

ASSISTANT: Ok, please wait.

USER: Could you please help me?

ASSISTANT: Sorry, no reservation found on your name to change.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.