You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am Kevin Wright here, I would like to travel from DCA to EWR, can you please help me to reserve my ticket?

ASSISTANT: Please provide your travelling dates.

USER: Ok, my dates of journey is from 04/23 to 04/25. Please make sure that the price limit is 500.

ASSISTANT: There is no flight for you with your route.

USER: Ok, no problem I will try with the another travelling agency.

ASSISTANT: Thanks for contacting us.

USER: Thank you for your service.