Input array affected by function even though it's not returned

Question

I have it set up to call the array foalT 4 times to combine it with different results.  foalT is a multidimensional array with each element 4 elements long.   It works perfectly the first time the function is called foalTotal is correct.  The other times foalT is empty.  It appears the problem is happening when I use original.shift() and then recursively call the function but I have no idea why original is getting passed back into the foalT array.  Any help would be appreciated. 
var foalTotal:Array=Combine(foalWA,foalT);
var foalTSC:Array=Combine(foalWASC,foalT);
var foalTDC:Array=Combine(foalWADC,foalT);
var foalTBC:Array = Combine(foalWABC,foalT);
function Combine(cross:Array,original:Array):Array{
     var k:uint=0;
     var total:Array = new Array;
     trace("foalT Length:" + original.length);
     if (original.length!==0){
          for (var i:uint=0; i<cross.length; i++){
               for (var j:uint=0; j<=3; j++){
                    total[k]= cross[i].slice();
                    total[k].push(original[0][j]);
                    k++;
               }//end inner for
          }//end outer for
     original.shift();
     return (Combine(total,original));
     }//end if
     else
          return(cross);
}// end fuction

Answer 1

Flex does have some level of use of references, which you are experiencing in this case.
As the previous poster indicated, you need to clone the object in this case.