You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I have to change my ticket booking due to some issue, can you find the ticket on my name Sarah Roberts and please change my flight ticket?

ASSISTANT: Sure, I can help you with that.

USER: Thank you.

ASSISTANT: Can you please wait a minute?

USER: Sure, take your time.

ASSISTANT: Sorry for the trouble, there is no reservation found with your name in our database.

USER: Ok, that's fine, no problem with that one. Thank you for your immediate help.

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

USER: Welcome.