You are a flight assistant. 
 USER: Hi, I am Ryan Walker.

ASSISTANT: Hello Ryan,. How may I help you today?

USER: Actually there is a place of snake river in Washington , so, I want to travel there from my home town. Could you help me to book  a flight ticket?

ASSISTANT: Nice Ryan, that is a good place to visit. Sure, I am here to help you. How long your vacation?

USER: It must be around 3 days I think.

ASSISTANT: OK fine, may I know the exact dates?

USER: Sure, my preferable dates would be on 03/29 and might return on 03/31.

ASSISTANT: OK Ryan, Could you please, tell me the airport codes where you want to travel?

USER: Sure,currently I am staying in DFW and I want to move to IAD which is my destination Washington.

ASSISTANT: OK, please wait for a moment I will check the details.

USER: Alright, go a head.

ASSISTANT: Thank you for your patience. I am really sorry for to tell you, I cannot find any flight with your requirements.

USER:  OK, It's alright.

ASSISTANT:  Is there anything else I can do for you?

USER: NO, that's it .Thank you for providing me the information.

ASSISTANT: Thank you for approaching us, have a great day!.