function addRow()
     {
          var obj=document.getElementById("tbl");
          var newNode = obj.children(0).cloneNode(true);
          obj.appendChild(newNode);
     }

     function delRow()
     {
          var obj=document.getElementById("tbl");
          if (obj.children.length>1) obj.removeChild(obj.children(0));
          else alert("I won't delete the first one!");
     }

function addRowToTable()
{
   var tbl = document.getElementById('tblSample');
   var lastRow = tbl.rows.length;
   // if there's no header row in the table, then iteration = lastRow + 1
   var iteration = lastRow;   
   var row = tbl.insertRow(lastRow);
   
   // left cell
   var cellLeft = row.insertCell(0);
   var textNode = document.createTextNode(iteration);
   cellLeft.appendChild(textNode);
   
   // right cell
   var cellRight = row.insertCell(1);
   var el = document.createElement('input');
   el.setAttribute('type', 'text');
   el.setAttribute('name', 'txtRow' + iteration);
   el.setAttribute('size', '40');
   cellRight.appendChild(el);
}
function removeRowFromTable()
{
   var tbl = document.getElementById('tblSample');
   var lastRow = tbl.rows.length;
   if (lastRow > 2) tbl.deleteRow(lastRow - 1);
}