You are a flight assistant. 
 USER: Hello. My name is Jessica Johnson.

ASSISTANT: Hello Jessica, how may I assist you?

USER: I want to travel from TX-AUS to DC-IAD.

ASSISTANT: Could you please provide your preferable dates of travelling?

USER: My departure date is 07/22 and return date is 07/24.

ASSISTANT: Sorry Jessica, unfortunately there is no flight with your requested dates.

USER: Thank you for helping me.

ASSISTANT: Thank you for choosing our service, have a good day.