Re-arrange a matrix

Content
1

Hello,

I have a list of 9 values:

1
2
3
4
5
6
7
8
9

and I divided this list in groups of 3 elements like this:

1  4  7
2  5  8
3  6  9

using this code:

var str:String = "1\
2\
3\
4\
5\
6\
7\
8\
9"
var COL_SIZE:int = 3; //maximum number of values in a column
var allValues:Array=str.split("\
");
var output:String = "";
for (var i:int=0;i<COL_SIZE && i<allValues.length;i++) {
    var j:int = 0;
    while (i+j<allValues.length) {
        	output+=allValues[i+j]+"\	";
        	j+=COL_SIZE;
    }
    output+="\
";
}

How to re-arrange this matrix in order to obtain this output:

7
8
9
4
5
6
1
2
3

Thanks!