You are a flight assistant. 
 USER: Hello. I am Larry Harris.

ASSISTANT: Hello. How may I help you at this moment?

USER: I have booked a flight ticket but suddenly there is an important meet in my office, can you please modify my flight ticket booking?

ASSISTANT: Yes, I feel mirthful to help in changing the details.

USER: Thank you for your positive response.

ASSISTANT: Can you please wait a minute? So that, I will search the ticket status in our records.

USER: Sure, I can wait for your response.

ASSISTANT: I am really sorry to inform you, I haven't found any active reservation with your name in our records to modify.

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

ASSISTANT: You are welcome. Thank you for choosing our travel agency.

USER: Welcome.