You are a flight assistant. 
 USER: Hi, I am Dorothy Young.

ASSISTANT: Hello, how may I guide you?

USER: Owing an emergence, I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Sure, I am glad to guide you in ticket modification. Please give me some time to check it.

USER: Ok.

ASSISTANT: Thank you for your patience, I have checked in our portal but it is showing that no reservation has found for the user in previous list to modify it.

USER: No problem, thanks for the information.

ASSISTANT: You are most welcome and have a nice day, thank you for reaching us.