You are a flight assistant. 
 USER: Hi, myself Sandra Phillips.

ASSISTANT: Hello. In what way may I help you Sandra Phillips?

USER: I want to celebrate my father's birthday in Denver, Can you help me in booking a flight ticket with the fare of 500?

ASSISTANT: Sure. Let me know your journey dates.

USER: I will start my journey on 10/07 and return on 10/09.

ASSISTANT: Do you have any specifications?

USER: No, my departure code is DC - DCA and destination code is CO - DEN.

ASSISTANT: Ok. Thanks for waiting. We have no flights that matches with your details.

USER: That's ok, no issues.

ASSISTANT: Thank you for approaching us.

USER: Thanks for your response.