You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Sarah Thomas here.

ASSISTANT: How may I guide you?

USER: Can you please help me out with altering my previous booking now?

ASSISTANT: Sarah Thomas, I am here to help you for this. Let me check your reservation status in our records.

USER: Ok, I will be waiting for your response.

ASSISTANT: Sorry for inconvenience, no reservation is found with your criteria.

USER: Oh! That's fine. Anyways, thank you for checking.

ASSISTANT: Thank you very much for approaching our agency.

USER: Most welcome.