I brought 2 concert tickets?

I brought 2 tickets to the bon jovi concert at the HP pavilion SJ thur craigslist, I met up with the guy and now i have the tickets how can I check if these tickets are valid, I did try to call Ticketmaster but they told me these tickets are brought thur ticket exchange, so I called them and they told me they cannot answer my questions because im the 3rd party , can anyone tell me how I can check these tickets