把一个下拉框中的选项添加到另一个中
1<html>
2 <body>
3 <form name="aa">
4 <table align="center">
5 <tr>
6 <td>
7 <select name="xuanze" size="6" style="width:80px">
8 <option value="海淀">海淀</option>
9 <option value="朝阳">朝阳</option>
10 <option value="东城">东城</option>
11 <option value="西城">西城</option>
12 <option value="宣武">宣武</option>
13 <option value="丰台">丰台</option>
14 </select>
15 </td>
16 <td align="center">
17 <input type="button" value="添加>>" onclick="javascript:add()"/>
18 <br>
19 <input type="button" value="<<删除" onclick="javascript:del()"/>
20 </td>
21 <td>
22 <select name="xuanzhong" size="6" style="width:80px"></select>
23 </td>
24 </tr>
25
26 </table>
27</form>
28 </body>
29 <script type="text/javascript">
30 function isexist(va){
31 var ee = false;
32 for(var i=0;i<document.aa.xuanzhong.options.length;i++)
33 if(document.aa.xuanzhong.options[i].value==va)
34 { ee=true; break;}
35 return ee;
36 }
37 function add(){//添加
38 for(var i=0;i<document.aa.xuanze.options.length;i++)
39 if(document.aa.xuanze.options[i].selected) {
40 if(!isexist(document.aa.xuanze.options[i].value)) //是否已经添加??
41 document.aa.xuanzhong.options[document.aa.xuanzhong.options.length]
42 = new Option(document.aa.xuanze.options[i].value,document.aa.xuanze.options[i].text);
43 }
44 }
45 function del(){
46 for(var i=document.aa.xuanzhong.options.length-1;i>=0;i--)
47 if(document.aa.xuanzhong.options[i].selected)
48 document.aa.xuanzhong.options[i] = null; //删除一个项目
49
50 }
51 </script>
52</html>
2 <body>
3 <form name="aa">
4 <table align="center">
5 <tr>
6 <td>
7 <select name="xuanze" size="6" style="width:80px">
8 <option value="海淀">海淀</option>
9 <option value="朝阳">朝阳</option>
10 <option value="东城">东城</option>
11 <option value="西城">西城</option>
12 <option value="宣武">宣武</option>
13 <option value="丰台">丰台</option>
14 </select>
15 </td>
16 <td align="center">
17 <input type="button" value="添加>>" onclick="javascript:add()"/>
18 <br>
19 <input type="button" value="<<删除" onclick="javascript:del()"/>
20 </td>
21 <td>
22 <select name="xuanzhong" size="6" style="width:80px"></select>
23 </td>
24 </tr>
25
26 </table>
27</form>
28 </body>
29 <script type="text/javascript">
30 function isexist(va){
31 var ee = false;
32 for(var i=0;i<document.aa.xuanzhong.options.length;i++)
33 if(document.aa.xuanzhong.options[i].value==va)
34 { ee=true; break;}
35 return ee;
36 }
37 function add(){//添加
38 for(var i=0;i<document.aa.xuanze.options.length;i++)
39 if(document.aa.xuanze.options[i].selected) {
40 if(!isexist(document.aa.xuanze.options[i].value)) //是否已经添加??
41 document.aa.xuanzhong.options[document.aa.xuanzhong.options.length]
42 = new Option(document.aa.xuanze.options[i].value,document.aa.xuanze.options[i].text);
43 }
44 }
45 function del(){
46 for(var i=document.aa.xuanzhong.options.length-1;i>=0;i--)
47 if(document.aa.xuanzhong.options[i].selected)
48 document.aa.xuanzhong.options[i] = null; //删除一个项目
49
50 }
51 </script>
52</html>