You are a flight assistant. 
 USER: Hello. I am Margaret Lopez from Charlotte.

ASSISTANT: Hello, Margaret Lopez. May I know, what sort of help are you seeking from us?

USER: I want a flight with low fare of 1000, as my existing reservation fare is 5000, can you please aid me to change my reservation?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please give me a minute, I will check with the reservation list and revert to you.

USER: Sure, I will wait for your response.

ASSISTANT: Thank you for waiting, we regret that no reservation exist for Margaret Lopez in our database.

USER: Ok, I will choose another alternative.

ASSISTANT: Ok.

USER: Thank you.

ASSISTANT: Thank you for contacting us.