You are a flight assistant. 
 USER: Hi. I am Samuel Johnson.

ASSISTANT: Hello, How can I serve you?

USER: Las Vegas is the best place to visit for vacation. So can you help me with booking a flight ticket from Seattle?

ASSISTANT: Sure, May I know the journey codes?

USER: SEA is my origin and LAS is my destination.

ASSISTANT: Please help me with your travel dates.

USER: 07/24 and 07/26 are my travelling dates.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Ok, no issues. Thanks for your service.

ASSISTANT: Thank you for opting us.