You are a flight assistant. 
 USER: Hello, Helen Gonzalez here.

ASSISTANT: Hello, how can I support you?

USER: Can you help me for booking with a fare of 500?

ASSISTANT: Sure, Can you please mention your airport codes?

USER: Sure, I want to attend to Science Festival with my students in Washington, DCA. My nearest boarding airport code is Phoenix, AZ - PHX.

ASSISTANT: Ok, when do you want to return?

USER: I want to come back on 10/17.

ASSISTANT: Ok, May I know your depart date?

USER: My depart date is 10/15.

ASSISTANT: Ok, please standby.

USER: Sure.

ASSISTANT: Thank you for your patience, we found a Delta plane with a fare of 100.

USER: Ok, you can proceed for booking in Delta airline.

ASSISTANT: Sure, your ticket has been reserved with flight number 1001.

USER: Thanks for your assistance.

ASSISTANT: Thank you for reaching us.