You are a flight assistant. 
 USER: Hello, I am Frank Perez.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me in booking the flight ticket from PHL to LAS?

ASSISTANT: Sure, can you please share me your travelling dates?

USER: I would like to travel on May 17 and return on May 19.

ASSISTANT: Do you have any class preference?

USER: No, I am comfortable with any of the class.

ASSISTANT: Is there any other specifications?

USER: My depart time should be morning.

ASSISTANT: Sorry, there were no flights with your given time.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.