javaScript操作select

注意:Option中的O是要大写的，不然语法报错 1.动态创建select       function createSelect(){ var mySelect = document.createElement_x("select");          mySelect.id = "mySelect";            document.body.appendChild(mySelect);      } 2.添加选项option      function addOption(){           //根据id查找对象，           var obj=document.getElementByIdx_x('mySelect');            //添加一个选项obj.add(new Option("文本","值"));    //这个只能在IE中有效         obj.options.add(new Option("text","value")); //这个兼容IE与firefox     } 3.删除所有选项option      function removeAll(){           var obj=document.getElementByIdx_x('mySelect');obj.options.length=0;      } 4.删除一个选项option function removeOne(){           var obj=document.getElementByIdx_x('mySelect');            //index,要删除选项的序号，这里取当前选中选项的序号 var index=obj.selectedIndex;obj.options.remove(index);     } 5.获得选项option的值 var obj=document.getElementByIdx_x('mySelect'); var index=obj.selectedIndex; //序号，取当前选中选项的序号 var val = obj.options[index].value; 6.获得选项option的文本 var obj=document.getElementByIdx_x('mySelect'); var index=obj.selectedIndex; //序号，取当前选中选项的序号 var val = obj.options[index].text; 7.修改选项option var obj=document.getElementByIdx_x('mySelect'); var index=obj.selectedIndex; //序号，取当前选中选项的序号 var val = obj.options[index]=new Option("新文本","新值"); 8.删除select       function removeSelect(){            var mySelect = document.getElementByIdx_x("mySelect");mySelect.parentNode.removeChild(mySelect);     }