AppendChild(cloneNode) Problem

I am working on a sortable table (full code in attachment). I solved all the intermediate steps till the end when, to my surprise, appenChild() method inserts some previous cloneNodes in looped rows in a peculiar mode, by leaving the end tags </tr> at the end of the table. So far:

1.- build the cloneNodes of the rows as an array, and each index as a paralel array:

//some needed variables on later
t=document.getElementById('tab');
nr=t.rows;
nc=t.rows[0].cells;

//array of rows and rows indexes
var oRows = new Array()
var iRows = new Array()
for(var i=1;i<nr.length;i++){
oRows[i]=t.rows[i].cloneNode(true);
iRows[i]=t.rows[i].rowIndex;
//so far so good, alert shows me what i needed
alert(oRows[i].innerHTML)
}

2. - build an array with the content of the correspondent cells on column and sort this array. The array is double and keep the genuine row's index for later use as each second element. Code: