js insertBefore
1 <select id="city" size="4" style="width:50px"> 2 <option id="hn">湖南</option> 3 <option id="hb">湖北</option> 4 </select> 5 <script type="text/javascript"> 6 /*创建"新元素",插入到"湖南"元素之前 7 var newOptionElement = document.createElement("option"); 8 newOptionElement.setAttribute("id","new"); 9 newOptionElement.innerHTML = "新元素"; 10 var cityElement = document.getElementById("city"); 11 var hnElement = document.getElementById("hn"); 12 cityElement.insertBefore(newOptionElement,hnElement); //新元素 13 */ 14 //创建"新元素",插入到"湖南"元素之后 15 var newOptionElement = document.createElement("option"); 16 newOptionElement.setAttribute("id","new"); 17 newOptionElement.innerHTML = "新元素"; 18 var cityElement = document.getElementById("city"); 19 var hnElement = document.getElementById("hn"); 20 21 //兄弟节点 nextSibling 22 cityElement.insertBefore(newOptionElement,hnElement.nextSibling); 23 </script>