You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how  may I help you?

USER: Owing an emergence, I want to change my existing reservation. Can you help me with it?

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

USER: My name is Thomas Hernandez.

ASSISTANT: Ok, give me a minute please.

USER: Sure.

ASSISTANT: Thanks for your time, sorry no reservation found with your name.

USER: Ok, no issues.

ASSISTANT: Thank you for reaching us, have a nice day.