You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you now?

USER: I got an information that during summer vacation Washington is best place to enjoy. Can you please book me a flight ticket from Seattle?

ASSISTANT: Sure, may I know your journey dates?

USER: 04/25 and 04/27 are my travelling dates.

ASSISTANT: Is there any price limit for you?

USER: Yes, price limit must be 500.

ASSISTANT: Please provide me your airport codes?

USER: Sure, it is from WA - SEA to DC - DCA.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to inform you that there is no flight found o your details.

USER: Ok, no issues.

ASSISTANT: May I know your good name please?

USER: Timothy Johnson is my name.

ASSISTANT: Thanks for opting us, have a great day.

USER: Thanks for your information.