JS给表格加行和JS操作HTML元素

其实很简单！！！

var t = document.getElementById('table_id');

var tr = document.createElement('tr');
var td = document.createElement('td');
td.innerHTML = "name:<input type='text' name='n' />";
tr.appendChild(td);
t.appendChild(tr);

操作HTML元素，把select换成input
先把select放到一个span中，然后

var s = document.getElementById("span_id");
var sel = document.getElementById("select_id");
s.removeChild(sel);

var new_sel = document.createElement("select");
new_sel.id="new_select_id";
new_sel.name="new_name";
new_sel.innerHTML="<option></...>";
s.appendChild(new_sel);