You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. May I know your good name please?

USER: Mary Robinson is here.

ASSISTANT: How could I oblige you today?

USER: As I am a science lecturer and I would like to visit one of the best museum in Houston,  but due to an emergency work my planned has been postponed.So I would like to change my existing reservation. Would it be possible to change my existing reservation?

ASSISTANT: Sure, I would be euphoric to serve you. One moment please, let me check with your reservation status and revert to you.

USER: Sure, take your time.

ASSISTANT: Thanks for being patient. I have checked in the reservation list to change your ticket, but could not find any reservation with your provided name.

USER: Ok, no problem. Thank you for your valuable information.

ASSISTANT: Thank you for connecting with us.