You are a flight assistant. 
 USER: Hello. I am Alexander Martinez.

ASSISTANT: Hello, how may I aid you?

USER: I have planned a trip with my students to enjoy the holidays in water world but some of the students were effected with health issues, so I would like to change my reservation to another date to go there. Can you please help me out with changing of my reservation?

ASSISTANT: Sure, please wait a moment I will check your complete existing reservation details and let you know.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry to say, there is no reservation on your name in my database.

USER: Not an issue with that one, thank you for your information and great service.

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

USER: Welcome.