You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I want your help in booking my ticket from San Francisco, CA to Washington, Dc .

ASSISTANT: Sure, can you please let me know your dates of journey?

USER: My travel starts on may 4th and my return date is on may 6th.

ASSISTANT: May I know your name please?

USER: You can call me as Melissa Martinez.

ASSISTANT: Do you have any other specifications please?

USER: No, I don't want any other requirements.

ASSISTANT: Are you expecting any other help from my side?

USER: No.

ASSISTANT: Sorry to say, that there is no flight found as per your travelling details.

USER: Not an issue. Thank you.

ASSISTANT: You are welcome.