You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. What type of assistance do you need from our travel agency?

USER: I am Jack Allen, would it be possible to change my reservation to new travelling dates?

ASSISTANT: Yes, it is possible to change the details once the previous ticket is found.

USER: Ok, thanks.

ASSISTANT: Can you please wait a minute?

USER: Yes, take your time.

ASSISTANT: Sorry for the trouble which is caused to you, there is no reservation found with your name in our system data to change the travelling dates.

USER: It's ok, thanks for your response and service.

ASSISTANT: It's my pleasure to help you. Thank you for approaching us.