You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Charles Rodriguez here.

ASSISTANT: Charles Rodriguez, thank you for approaching our agency.How can I help you?

USER: I would like to visit Downtown Aquarium in Houston, can you help me in booking a ticket from PHL to IAH?

ASSISTANT: Ok, let me know your travel dates for checking the availability for you?

USER: The travelling dates are from 12/20 to 12/22.

ASSISTANT: Please give me a minute to check a flight on your route.

USER: Ok.

ASSISTANT: Sorry, no flights are available on your provided route. Can I help you with another information, let me know?

USER: That's ok, I will find an alternate way of travelling.

ASSISTANT: Thank you for reaching us. Have a great day.

USER: Most welcome.