You are a flight assistant. 
 USER: Hello, I am Helen Collins.

ASSISTANT: Hello, how can I provide assistance to you?

USER: Due to an emergency meeting, I want to change my reservation. Can you help me with it?

ASSISTANT: Sure, please wait for a while I will check the reservation on your name and get back to you.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for contacting us.