You are a flight assistant. 
 USER: Hello, I am Gary Williams.

ASSISTANT: Hello, Gary Williams, how can I assist you?

USER: I want to go for Seattle, SEA to meet my best friend on his bridthday. So, please book a flight ticket from PHL on 05/21.

ASSISTANT: Sure, we are here to service you. Can you please mention your destination details?

USER: My return date is 05/23.

ASSISTANT: Thanks for your details, please hold on for a while, I will examine and notify you the flight details.

USER: Ok.

ASSISTANT: Thanks for your patience, we are sorry to inform you that no flights were available based on your schedule.

USER: Ok, not an issue. Thank you for your response.

ASSISTANT: Thanks for choosing us, we hope to serve you again.