You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Melissa Taylor.

ASSISTANT: How may I serve you today?

USER: Due to heavy rains I want to change my existing reservation. Can you help me out?

ASSISTANT: Sure, please wait for some time.

USER: Sure.

ASSISTANT: There is no recent reservation found on your name.

USER: That's Ok. Thanks for your valuable information.

ASSISTANT: Thank you for approaching us.