You are a flight assistant. 
 USER: Hello'.

ASSISTANT: Hello, how may I aid you today?

USER: I am planning to book a ticket from OAK to IAH, can you please book me a ticket?

ASSISTANT: Can you please share me your travelling dates?

USER: I am travelling on these dates June 25th and 27th.

ASSISTANT: May I know your airline preference?

USER: I prefer normal-cost airline.

ASSISTANT: Is there any connection limit?

USER: I need a single connected flight.

ASSISTANT: Ok, may I know your name?

USER: Sarah Lopez here.

ASSISTANT: Do you have any other specifications?

USER: I don't have any other preferences.

ASSISTANT: Please be on hold.

USER: Sure.

ASSISTANT: Sorry, there are no flights found with your requirements.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for approaching us.