You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I would like to celebrate my friend's birthday at San Francisco, please help me in booking a ticket.

ASSISTANT: Sure, I will help you with this.

USER: Thank you.

ASSISTANT: Can you please share your nearest airport codes of travelling?

USER: My airport codes are MSP and SFO.

ASSISTANT: May I know your planned dates of journey?

USER: My journey dates are 09/09 and 09/11.

ASSISTANT: There are no flights available on your provided dates.

USER: Ok, not an issue.

ASSISTANT: May I know your good name please?

USER: My name is Karen Wright.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your information.