You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: My name is Daniel Mitchell. I am planning to travel from DEN to IAH to attend my sister's wedding, could you please help me with booking a flight ticket?

ASSISTANT: Sure, on which date you are  planning to visit?

USER: My journey dates are 10/28 and 10/30.

ASSISTANT: Sure, give me a minute.

USER: Ok.

ASSISTANT: Sorry to say that there is no flight  found.

USER: That's ok. Thank you for the information.

ASSISTANT: Thank you for contacting us.