You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Ruth Martinez here.

ASSISTANT: How may I assist you today?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, please wait for a minute.

USER: Ok.

ASSISTANT: Sorry, I could not find any reservation with your name in our database.

USER: Ok, not a problem. Thank you.

ASSISTANT: My pleasure.