Okay.. Well since you are new I don't really know what to say. First off that is a bad call under any conditions. I think there's a section in No Limit Hold 'Em Theory and Practice that talks about calling all in bets preflop, but I haven't gotten to it yet. What you have to think about is the range of cards that they'll be playing the way that they do, then see how your hand compares to their range. The shorter stacked you get the better pot odds you have to make the call, but you're still way to deep to be stacking off J10s preflop. Infact, the only time where you would get it all in is in a tournament (under conditions, of course), but never a cash game. I don't know how he was playing, but you J10s isn't ever really doing good against anyone's preflop shoving range, even at 2nl.