You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you?

USER: I have a job opportunity  in San Francisco, could you help in booking a ticket?

ASSISTANT: May I know your airport codes?

USER: My airport  codes are from IAH to SFO.

ASSISTANT: May I know your preferable dates?

USER: My preferable travelling are from 10/26 till 10/28.

ASSISTANT: May I know your name?

USER: Myself Lisa Mitchell.

ASSISTANT: Sorry Mitchell ,there is no flight with your requirements.

USER: It's ok, no issues.

ASSISTANT: Thank you for contacting us.

USER: Thank you for service.