js中onchange（）的使用，实现功能，选择哪一张图片，显示哪一张

 1 DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 2 html xmlns="http://www.w3.org/1999/xhtml">
 3 head>
 4 meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 5 style >
 6     
 7     body{text-align:center}
 8     div{align:center}
 9 
10 
11 style>
12 title>无标题文档title>
13 head>
14 
15 body>
16 
17 select id="option" onchange="change()">
18     option value="1">图片1option>
19     option value="2">图片2option>
20     option value="3">图片3option>
21     option value="4">图片4option>
22     
23 select>
24 br />br />br />br />
25 div class="images" width="790px" >
26     div align="center">
27         img id="1"width="790px" height="340px" src="../../课堂练习/js03/59a7a48aN7a42d3fe.jpg" style="display:block"/>
28         img id="2"width="790px" height="340px" src="../../课堂练习/js03/59cc929fNaebef801.jpg" style="display:none"/>
29         img id="3"width="790px" height="340px" src="../../课堂练习/js03/59ccc986Nbf17e33e.jpg" style="display:none"/>
30         img id="4"width="790px" height="340px"src="../../课堂练习/js03/59ccec77N64688a8d.jpg" style="display:none"/>
31     div>
32 div>
33 script>
34     function change(){
35         var opt=document.getElementById("option");
36         if(opt.value=="1"){
37             var images=document.getElementsByTagName("img");
38             for(var i=0;iimages.length;i++){
39                 if(images[i].id==1){
40                 images[i].style.display="block";
41             }else{
42                 images[i].style.display="none";
43             }
44             }
45         }
46         if(opt.value=="2"){
47             var images=document.getElementsByTagName("img");
48             for(var i=0;iimages.length;i++){
49                 if(images[i].id==2){
50                 images[i].style.display="block";
51             }else{
52                 images[i].style.display="none";
53             }
54             }
55         }
56         if(opt.value=="3"){
57             var images=document.getElementsByTagName("img");
58             for(var i=0;iimages.length;i++){
59                 if(images[i].id==3){
60                 images[i].style.display="block";
61             }else{
62                 images[i].style.display="none";
63             }
64             }
65         }
66         if(opt.value=="4"){
67             var images=document.getElementsByTagName("img");
68             for(var i=0;iimages.length;i++){
69                 if(images[i].id==4){
70                 images[i].style.display="block";
71             }else{
72                 images[i].style.display="none";
73             }
74             }
75         }
76         
77         
78         
79     }
80 
81 script>
82 
83 body>
84 html>