You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you ?

USER: My name is Donna Martinez.

ASSISTANT: Yes, Donna Martinez.

USER: I want to visit my friend this summer, could you help me in booking the ticket?

ASSISTANT: That's good, could you provide me your travelling details?

USER: It's from EWR to OAK.

ASSISTANT: Ok, dates of travelling please?

USER: The dates of travel are 06/30 to 07/02.

ASSISTANT: Sorry Donna, there is no flights on your required one.

USER: That's ok. Thank you for your time.

ASSISTANT: Thank you for contacting us.