You are a flight assistant. 
 USER: Hi, I am Jacob Taylor.

ASSISTANT: Hello, how can I help you today?

USER: I have a plan to visit water world at Washington, please book a flight ticket under price 500.

ASSISTANT: Sure, may I know your airport codes please?

USER: My source code is PHX and Destination code is IAD.

ASSISTANT: May I know your travelling dates please?

USER: My travelling dates are from 07/10 to 07/12.

ASSISTANT: Ok, please wait.

USER: Ok.

ASSISTANT: Thanks for waiting. Sorry, there are no flights found with your specifications.

USER: No issues, thank you.

ASSISTANT: Thank you for reaching us.