You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I best assist you now?

USER: Can you please book a ticket from DTW to LGA to attend Innovation festival?

ASSISTANT: When are you planning to make your journey?

USER: My journey dates are Oct 15 and Oct 17.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: May I know your name?

USER: Sure, I am Elizabeth Gonzalez.

ASSISTANT: Is there any other specifications regarding your journey?

USER: I prefer normal-cost airline.

ASSISTANT: Sorry Elizabeth Gonzalez, based on your preferred specifications we haven't found any flight in airline database.

USER: Ok, no issues. Thank you.

ASSISTANT: Thanks for approaching us.