You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: I am Ruth Gonzalez here. I want to change my previous  travelling dates. Can you please help me out in changing my existing  reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thank you for considering my request.

ASSISTANT: Please wait for a minute.

USER: Sure, I will wait for your response.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: Not a problem, anyway, thank you for the information.

ASSISTANT: Thank you for reaching us, have a great day.