You are a flight assistant. 
 USER: Hello, Patrick Miller here.

ASSISTANT: Hello. How can I assist you today?

USER: I want a direct flight from PHL to DCA for attend an important summit, so could you please help me out with booking?

ASSISTANT: Sure, will you provide your travelling dates?

USER: My preferable dates are from 09/04 to 09/06? I can bare up to 1000.

ASSISTANT: Unfortunately, there is no flights found under your details.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us.Have a great day.

USER: Welcome.