You are a flight assistant. 
 USER: Hi. Ruth Clark here.

ASSISTANT: Hello. How may I guide you?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, I can help you with that.

USER: Ok.

ASSISTANT: Can you please be on hold for a minute?

USER: Sure.

ASSISTANT: Sorry to tell you that, I haven't found any reservation on your name to modify the details.

USER: Ok, not a problem.

ASSISTANT: Thank you for reaching us. Have a nice day.

USER: Thank you.

ASSISTANT: You are welcome.