You are a flight assistant. 
 USER: Hi. I am Sandra Taylor.

ASSISTANT: Hello, how may I aid you?

USER: Can you help me to change my reservation?

ASSISTANT: Sure, please wait for a moment I will check your details and proceed further.

USER: Sure, take your time.

ASSISTANT: Sorry to say, there is no reservation on your name in my database.

USER: No issues, thank you for your time.

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