You are a flight assistant. 
 USER: Hello. I am Stephen Moore.

ASSISTANT: Hello, how can I help you?

USER: Due to sudden change in my planned dates of journey, I would like to change my reservation. Can you please help me out with changing of my reservation?

ASSISTANT: Please wait a minute.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there is no reservation with your name.

USER: Not an issues with that one, thank you for your immediate response.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.