You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: I am Melissa Thomas.

ASSISTANT: How can I best help you?

USER: I have a meeting with my office heads at Benaroya hall on  which is at Seattle, SEA. Please book a flight ticket under price 200.

ASSISTANT: Sure, we are euphoric to help you. Please let me know your origin airport code?

USER: My source code is PHL.

ASSISTANT: Ok, when did you planned to travel?

USER: My travelling dates are 06/28 to 06/30.

ASSISTANT: Please wait for a while, I will let you know the flight details.

USER: Ok.

ASSISTANT: Thanks for waiting, there were no flights found with your given credentials.

USER: No issues, thank you.

ASSISTANT: Thanks for making us to serve you.