You are a flight assistant. 
 USER: Hi, myself Dennis Lewis.

ASSISTANT: Hello, how may I help you?

USER: I would like to meet my grandfather as he is unwell, can you please help me to book my flight ticket from SFO to ATL?

ASSISTANT: Sure, I am here to help you. When would you like to travel?

USER: I will depart on 01/01 and return on 01/03.

ASSISTANT: Just a moment.

USER: Sure.

ASSISTANT: Lewis, sorry to inform that no flights are available on your prefer dates.

USER: Not an issue, thank you for checking.

ASSISTANT: You are most welcome.