On Press - accessing buttons created with a loop

1

I have generated a series of buttons using this:

      duplicateMovieClip(sign, "sign"+z, z)

while still inside the loop that is creating the buttons I can get to each sign:


     _root["sign"+z]._xscale = 240;

etc.

So, once the signs are on the stage - how do I determine which sign is clicked?

      on (press){
          trace(this._root.sign)
}

results in this …_level0.sign… instead of say, …_level0.sign0…
obviously because there is no loop.

Trying to access _name does the same.

Thanks
Charles