You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Actually I am trying to modify the details in my previous ticket which is booked in the last week but due to some server problem, I am not getting that. Can you please help me in changing?

ASSISTANT: Sure, I am glad to assist you in modifying the ticket details. Can you please tell me your name?

USER: Sure, I am Donna Thomas.

ASSISTANT: Ok. I am happy to inform you, I found your past ticket in our chart list. What are your changed travel dates?

USER: Sure, my planned trip dates are 12/23 and 12/25.

ASSISTANT: Ok, can you please mention the airport codes that you prefer to travel?

USER: Ok, my airport codes from IAH to MSP.

ASSISTANT: Sorry to tell you, the flights are no running on the dates you have given because there is a cyclone effect in that area.

USER: Ok, not a problem. Anyway's thank you for your information.

ASSISTANT: You are welcome. Have a nice day.