You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello,.

USER: I am John Hernandez.

ASSISTANT: How may I render you?

USER: Can you please make a flight reservation from TX - DFW to NY - LGA?

ASSISTANT: Sure, do you have any price limit?

USER: Yes, it is 500.

ASSISTANT: Help me with the trip dates?

USER: I will fly on 06/25 and return on 06/27.

ASSISTANT: Thanks for your details, there were no flights found based on your given details.

USER: Ok, thanks for your help.

ASSISTANT: Thanks for reaching us, have a nice day.