Looping through instance names in a movieclip

1

When I want to loop through instance names like: “tile1”, “tile2” etc.
I use a code like this:


for(var i=0;i<=10;i++)
{
   this["tile"+i]._x=300;
}

but when I put these MC’s inside an MC (which I’ve named: “ground”) for some reason this code:


for(var i=0;i<=10;i++)
{
   _root.ground.this["tile"+i]._x=300;
}

doesn’t work.

WHY?

and another question, is there a way to loop through all the objects inside a movieclip without giving each one an instance name?

thanks.