You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: As I have planned a holiday trip with my friends on 09/29 but, suddenly I need to attend a client meeting in head quarters, so I need to change my reservation. Can you assist me in this?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Can I have your name to proceed further?

USER: Joshua Miller is my name.

ASSISTANT: Ok, please wait a moment, let me check your reservation and let you know.

USER: OK.

ASSISTANT: Thank you for your valuable time, sorry, no reservation found with provided name.

USER: Ok, no issues in that. Thanks for your response.

ASSISTANT: Thank you for availing us.