Need Actors to know each others states

Hi I have two actors in one scene and what I'm trying to do is click on one and it will do nothing if the other actor is still on the screen but destroy itself if the other actor is not on the screen. How can I do this without creating a second scene?
Comments
make an actor, and drag then around the scene
when overlaps or collide with actor, change attribute to 1
when touch is press and attribute is 1, destroy this actor
Calvin
Also is it the Actor I just created that I set to when overlaps or collide with actor?
Finally when you say "change attribute to 1" when I create a new rule for new actor and I select "overlaps or collide with actor" the only option next to it is with "actor of type" What steps do I need to take to change attribute to 1.
Thanks again as I said I'm a newbe to GS so I do appreciate the help you guys give.
use the change attribute behaviors
Calvin
I think what Calvin is trying to say is...
In the top left section where your actors are displayed there is a tab called attributes. Open this tab and click the plus sign below in the bottom left corner of the window to create a new attribute of type integer. Call this attribute something like "off screen?"
You then create a new actor back in the actors tab - "out of scene". It can be a big white block or whatever. Copy it 3 times and "box" your scene in around the edges, so the blocks are not on your viewable area but surrounding it.
For when your wandering actor goes off the edges.... Make a rule in your "out of scene" actor that says, when actor overlaps or collides with actor of type "wandering actor", and drag a constrain attribute behaviour into the rule's consequence. You're going to want the attribute "off screen?" to constrain to 1 when actor overlaps, otherwise "constrain attribute" to 0.
Finally, In the other actor that you want to have differing properties, put in a rule that says, when "off screen?" is equal to 1, AND actor receives touch, destroy actor.
Of course, this depends entirely on the context of what you want these things to do, you may want to be careful of your wandering actor strolling on forever off the edge of the screen and out of your out of scene box or whatever. Also I'm not sure why you would use an integer and not a boolean (true or false - same principle but true and false instead of 1 and 0 for integer) as I've tended to do for most things, but I'm new myself; perhaps an older and wiser member can tell you better, but I think this should work in the meantime...
Cheers.
I'm sorry if I sound stupid but drag around scene doesn't mean anything else to me. Also when I create change attribute I don't see an option to change numbers just see game devices actor 1.
When someone has been using something for a while you can forget that new users won't follow that same train of taught as you and where you wouldn't even think of saying ok click here and then here because its second nature to you to me its not.
I understand if you don't have time to explain step by step what you mean so if anyone else can explain or link to a tutorial where those steps are in it that would be helpfull.
Make a new attribute of type boolean as per above instructions and call it "Ball 1 Gone?".
In your behaviours for Ball 1 (left side ball), create a rule that says when actor is touched, destroy actor, and additionally in the same rule, constrain attribute, game---> "Ball 1 Gone?" to true, otherwise, constrain attribute "Ball 1 Gone?" to false.
Then in Ball 2 (right side ball), create a rule that says when actor is touched, AND "Ball 1 Gone?" is true, destroy actor.
I think this should work (though I will cover myself by re-iterating I'm a noob myself!) so let us know.
Cheers!
yep that is about it , I think it will work
this will be useful:http://www.youtube.com/user/GameSaladCookbook#p/
Calvin