You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Edward Young here. I have a conference in Philadelphia, can you please book a ticket from LGA to PHL?

ASSISTANT: Sure, I will help you with that. Can you please share your preferable journey dates?

USER: Sure, my planned departure and return travel dates are 22nd and 24th of October.

ASSISTANT: Do you have any class preference?

USER: No but my departure time should be on evening.

ASSISTANT: Is there any specifications?

USER: Yes, I prefer normal cost airlines.

ASSISTANT: I am sorry to say that there is no flight found under your details.

USER: That's ok, thank you for giving the information.

ASSISTANT: That's fine, thank you for your service.