You are a flight assistant. 
 USER: Hi. I am Charles Carter.

ASSISTANT: Hello, what can I do for you best?

USER: I am a traveller and I would like to explore the new places in Los Angeles.So I would like to fly from Washington. Could you please make a airline reservation?

ASSISTANT: Ok, I can help you in making a reservation. May I know your budget for the ticket?

USER: I can spend upto 500.

ASSISTANT: May I know your depart and arrival dates?

USER: My depart will be on 06/18 and arrival on 06/20.

ASSISTANT: I need your source and destination airport codes?

USER: My source code is DC-IAD and destination code is CA-LAX.

ASSISTANT: Sorry, no flights are available on those dates.

USER: Ok, no issues.

ASSISTANT: Thanks for reaching us, hope to serve you better next time.

USER: Thank you for your service.