Altering the alpha of the member of an array

programming flash
1

I want to set all the movieclips that belong to the objects in an array to .5 .
The array is enginesForSale.

for (var i:Number = 0; i < _model.enginesForSale.length; i++)                        
{
       var callName:String = _model.enginesForSale*.name;
     [COLOR=#0000cd] // at this point callName would be set to "hE1"[/COLOR]
        //_model.enginesForSale*.alpha = .5;[COLOR=#0000cd]//this is talking directly to the object rather than the movieclip
[/COLOR]
           [COLOR=#0000cd]//put this part in cause i'm getting the null object reference[/COLOR]
        if (_model.enginesForSale* != null)
          {
                    trace("v752 alphaDown");[COLOR=#0000cd]//this traces[/COLOR]
          
                    asBaseScreen.getChildByName(_model.enginesForSale*.name).alpha = .5;   
              [COLOR=#0000cd]//this still gets null object error  
// if i did this directly it would say asBaseScreen.hE1.alpha=.5;
[/COLOR]
           }
                        
}