Can't be much more specific then the subject line lol. I'm trying to detect 3 or more matching values in an array grid, vertically and horizontally... then flagging the value of the x/y in the grid with -1 or something, so the entity corresponding to that point on the array can destroy itself, add points, and reset the position on the array/grid back to empty. If that makes sense... my brain hurts.
Sounds to me like you're looking for Match-3 mechanics. Rexrainbow has made an example using his own plugins. It's very flexible, but may not be too well suited for beginners.
I also made a little plugin using the jMatch3 lib. It is less flexible, but easier to use in my opinion.
Of course you can do this purely with events. I've done several Match-3 engines this way. Basically you just loop through a row/column (pretty much like Majinboo shows with the For-loop), have a variable hold the number of matches, which you get by comparing to the previous piece. If you reach a number of three are greater you have a match.