You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: I am Ruth King.

ASSISTANT: How shall I help you?

USER: I need to book a ticket to meet my parents with fare of 500. Could you please help me in doing that?

ASSISTANT: Please provide your travelling dates?

USER: My travelling dates are 11/11 and return on 11/13.

ASSISTANT: Please mention your travelling codes?

USER: My travelling airport codes are IAD to DFW.

ASSISTANT: No flights found.

USER: Fine, thank you.

ASSISTANT: Thank you.