You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Jennifer Nelson.

ASSISTANT: How can I assist you today?

USER: Due to some urgent office meeting, I am going to change my existing reservation. Can you please help me with that?

ASSISTANT: Sure, I can help you with that. Please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Nelson, there is no reservation found under your name to do changes in that.

USER: Not a big problem, anyhow thank you very much for your service.

ASSISTANT: Thank you for choosing us.