You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Benjamin Hill.

ASSISTANT: How may I assist you today?

USER:  can you assist me to book my flight ticket to attend a conference with my clients in Seattle city in the month of April?

ASSISTANT: Sure, may I know your travelling airport codes?

USER: My source is CLT and landing airport code is SEA.

ASSISTANT: Mention your travelling dates a please.

USER: My trip dates are 04/19 to 04/21.

ASSISTANT: Do you need any connecting flights for this booking?

USER: Yes, and make sure my departure time should be afternoon.

ASSISTANT: May I know budget for this trip?

USER: My fare is 500.

ASSISTANT: Base on your requirements there are no flights running on your journey dates.

USER: No issue, thank you for checking.

ASSISTANT: Thank you for reaching our service.