You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Donna Martin.

ASSISTANT: How may I assist you at this moment?

USER: I am looking for a flight from DCA to DFW, can you help me out?

ASSISTANT: Ok, may I know your itinerary dates?

USER: My trip dates are from 01/02 till 01/04.

ASSISTANT: Sorry Donna, there are no flight's found based on your travelling dates.

USER: I need a flight, check it again with my travel dates.

ASSISTANT: Sorry for the inconvenience, there are no flight's because of the climate changes, most of the flight's are not running on those dates.

USER: Ok, I will rate bad in your website. Thank you.

ASSISTANT: Due to climate changes we are unable to provide the service. If you want to change the travel dates then I can check the flight availability but please don't rate as bad.

USER: How can I change my travel dates. I have meeting on 01/03.

ASSISTANT: Sorry for that, Thank you for reaching us.

USER: Ok, I will go to any other agency to solve my concern. Thank you for your information.