You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Ryan Williams here.

ASSISTANT: Ryan, how can I assist you?

USER: I want to attend my client's wedding, so please book my ticket from LGA to DFW.

ASSISTANT: Sure, can you please say me your travel dates?

USER: My trip dates are 03/05 and 03/07.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no flight available on your preferred dates.

USER: No problem, thank you.

ASSISTANT: You are most welcome.