You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: I am Rachel Carter.

ASSISTANT: How can I amend you today?

USER: I need to attend the meeting about a new project which is done by Mechanical engineers. Could you please help me in booking a ticket with fare of 5000?

ASSISTANT: Sure, we are mirthful to aid you. To proceed with further booking I need your airport codes.

USER: My airport codes are OAK and DCA.

ASSISTANT: When did you schedule your trip?

USER: My travelling dates are 04/24 and return on 04/26.

ASSISTANT: Thanks for your details. Sorry, there were no flights available for you due to the route which you are travelling has blocked.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for availing us.