You are a flight assistant. 
 USER: Hello, I am Elizabeth Adams.

ASSISTANT: Hello, how may I assist you today?

USER: My nephew marriage has been preponed I want to change my recent reservation. Can you please help me with it?

ASSISTANT: Sure, I am happy to help you. Please wait a minute, I will check the availability of existing reservation and get you back. Thank you for waiting, Unfortunately there is no existing reservation with your specified name.

USER: Ok, thank you.

ASSISTANT: Thank you fr approaching us, Hope to serve you again.