You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you at this moment?

USER: Due to an emergency, I have to cancel my previous flight ticket, can you please help me with that one?

ASSISTANT: Sure, I will help you with that. Can you please mention your name for further process?

USER: Thank you for accepting my request and I have done the booking on my name John Green.

ASSISTANT: Ok, please hold on a moment.

USER: Sure, I will be waiting for your response.

ASSISTANT: There is no previous reservation available under your name.

USER: No problem with it. Thank you for your assistanace.

ASSISTANT: Thank you for reaching us.

USER: Welcome.