51help TIY
码：
<html> <head> <script type="text/javascript"> function insertBeforeSelected() { var x=document.getElementById("mySelect"); if (x.selectedIndex>=0) { var y=document.createElement('option'); y.text='Kiwi'; var sel=x.options[x.selectedIndex]; try { x.add(y,sel); // standards compliant } catch(ex) { x.add(y,x.selectedIndex); // IE only } } } </script> </head> <body> <form> <select id="mySelect"> <option>Apple</option> <option>Pear</option> <option>Banana</option> <option>Orange</option> </select> <input type="button" onclick="insertBeforeSelected()" value="Insert option before selected" /> </form> </body> </html>
查看结果: