Select object extension?

In my game, there are rocks and other objects on the ground to pick up and throw. The problem is, if there is more than one rock on the ground and the player goes to pick one up, the player picks up all of the rocks at once, and when throwing them they all start to glitch up. I know the problem is because all the rocks are sharing the same values (I just made one rock object and then duplicated it a few times), so how do I give them seperate values? I've read of using select object extension, but I can't figure out how to use it for what I need to do. Thanks for any help. Also, I've already made a ton of events for all objects to pick up and throw, would I have to totally re-do them to add seperate values?

You should spread vale on the rocks to give them seperate ID's.

I've read of using values as an ID but I'm not sure how to do that properly, could someone fill me in on the details?

When you spread a value, let's say Alterable Value A, and base it on 1, the first created active will have a Alt Value 1. You can spread the value under your active in the event editor. You can also used a fixed value of an active.

User clicks on active
Counter: Set a counter in your fram and set it to the alt value or fixed value.

Counter is equal to (Alt Value or fixed value)
Do stuff

Here. Take a look at this: http://www.clickteam.com/epicenter/ubbthreads.php?ubb=showflat&Number=112755#Post1127 55

download that file, it uses ID'ing