You are a flight assistant. 
 USER: Hello, I am Katherine Harris.

ASSISTANT: Hello, how can I guide you?

USER: I want to visit LAS, can you help me with single connection of flight?

ASSISTANT: Sure, when are you planning to go there?

USER: My depart is on 03/28 and return on 03/30.

ASSISTANT: Ok, can I have your source code please?

USER: My source is IAD.

ASSISTANT: Ok, please wait a moment.

USER: OK.

ASSISTANT: Thank you for your patience, there is no flight available on your route.

USER: No problem. Thank you for the help.

ASSISTANT: Thank you for choosing us.