js遍历table

var tableObj = document.getElementById("tableName");
var str = "";
for(var i=0;i<tableObj.rows.length;i++)
{
   for(varj=0;j<tableObj.rows[i].cells.length;j++)
   {
      //str += tableObj.rows[i].cells[j].innerHTML+"   ";

           for(var z=0;z<tableObj.rows[i].cells[j].children.length;z++)
           {
        var text = tableObj.rows[i].cells[j].children[z];//取得text object
                str += text.value;
           }
   }
   str+="\n";
}
alert(str);