You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Charles Lewis.

ASSISTANT: How can I help you, Lewis?

USER: I wish to visit the Grand Canyon in Nevada. Can you help me in booking a ticket?

ASSISTANT: That's really a nice place to visit, may I know your take off and landing airport codes?

USER: The airport codes are MCO and LAS respectively.

ASSISTANT: On which dates are you planning to travel, Lewis?

USER: I am planning my journey on 11/20 and return on 11/22.

ASSISTANT: Give me few seconds to check the best flight service for you.

USER: Sure.

ASSISTANT: There is a flight available for you, in which ticket fare is about 600. Is it ok for you?

USER: I can't afford 600 as it exceeds my budget. Please don't confirm the ticket. Thank you for the information.

ASSISTANT: My pleasure, thank you for choosing us.