You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Eric Gonzalez from Washington.

ASSISTANT: How can I help you?

USER: I want to change my travel dates in my previous reservation. Can you please help me with that?

ASSISTANT: Please wait for a moment.

USER: Ok, thank you for your positive response.

ASSISTANT: Sorry,  there is  no reservation available under your name in our datebase.

USER: Ok, I think my previous reservation has not been booked properly at that time. Thank you for your service.

ASSISTANT: Most welcome.