javascript: change the content of table

1.change content 

var table = document.getElementById("TableData1");
 var enab = document.getElementById("alr_"+alr_id).value;
 table.rows[tab_line].cells[0].innerHTML="<input type='checkbox' class='standardTxt' id='set_enab' "+(enab=="true"?"checked":"")+" />";
 

2. insert row

function addRow()

{

　　//添加一行

　　var newTr = testTbl.insertRow();

　　//设置行背景

　　newTr.bgColor = '#008040';

　　//添加两列

　　var newTd0 = newTr.insertCell();

　　var newTd1 = newTr.insertCell();

　　//设置列内容和属性

　　newTd0.innerHTML = '<input type=checkbox id="box4">';

　　newTd1.innerText= '新增加的行';
}
</script>

3. dom insert row

var tb = document.getElementById("mailtable");
 var row = document.createElement("tr");
 var cell0 = document.createElement("td");
 cell0.className = "standardTxt";
  cell0.innerHTML = "a";
 var cell1 = document.createElement("td");
 cell1.align = "right";
 cell1.className = "standardTxt";
 cell1.innerHTML = ";
 row.appendChild(cell0);
 row.appendChild(cell1);
 tb.tBodies[0].appendChild(row);

4. add more rows

function insertRows(rows){
 document.getElementById("div_mailtable").innerHTML=
  "<table id='mailtable' width='100%' cellpadding=0 cellspacing=0 border=0>"
  +"<tbody id='body_mailtable'>"+document.getElementById("mailtable").tBodies[0].innerHTML+rows+"</tbody></table>";
}