Dynamically Appending Child At A Specified Position....?

i want to dynamically add rows to my table body using javascript, which am able to do. but there is a problem. for ex.

three rows
1
2
3

if i delete second row
1
3
if i want to add one more row.., then it should be row 2 with number 2.
---------------------------------------------
var totChkTable = document.getElementById('TABLE');
row=totChkTable.tBodies[0].appendChild(document.createElement('<tr >'));
..
....
cell=document.createElement('td');
---------------------------------------------

In each row ther r 6 colums, so i need a way where i can append my child in b/w.