JS代码问题

function checkapp(obj){
                 for (var i=1;i<21,i++)
                 {
                  var s=document.getElementById("image_"+i);
                  if (s.src=="'../image/'+i+'.png'")
                 s.src='../images/'+i+'.png';
                 }
                 var img=document.getElementById("image_"+obj);
                 img.src="../image/"+obj+".png";
                 }
总共有20张图片，id'image_1'以此类推，要求当鼠标放上后路径从../images/1.png改成../image/1.png每次显示一个
现在图像不能改变！
附上HTML：
<html>
     <head>
         <title>他们的声音</title>
         <link rel="stylesheet" href="css.css" type="text/css" media="screen" />
         <script type="text/javascript" src="./js.js"></script>
         <script language="javascript">
                 function checkapp(obj){
                 for (var i=1;i<21,i++)
                 {
                  var s=document.getElementById("image_"+i);
                  if (s.src=="'../image/'+i+'.png'")
                 s.src='../images/'+i+'.png';
                 }
                 var img=document.getElementById("image_"+obj);
                 img.src="../image/"+obj+".png";
                 }
         </script>
     </head>
     <body onload="locate()">
     <img src="./header.png" style="display:block">
     <h5 style='margin-top:20px; margin-left:40px;'>他们都和阶梯365一起成长</h5>
     <img src="../map.png"/ id='map'>
     <a href="#" id="center">现在加入和他们一起成长</a>
     <img src="../images/1.png"  onmouseover="checkapp(1)"  id="image_1"   style='position:absolute; left:430px; top:350px;'>
     <div id='d0'><em></em><span></span></div>
     <img src="../images/2.png"  onmouseover='checkapp(2)'  id='image_2'   style='position:absolute; left:280px; top:315px;'>
     <img src="../images/3.png"  onmouseover='checkapp(3)'  id='image_3'   style='position:absolute; left:515px; top:310px;'>
     <img src="../images/4.png"  onmouseover='checkapp(4)'  id='image_4'   style='position:absolute; left:320px; top:630px;'>
     <img src="../images/5.png"  onmouseover='checkapp(5)'  id='image_5'   style='position:absolute; left:740px; top:370px;'>
     <img src="../images/6.png"  onmouseover='checkapp(6)'  id='image_6'   style='position:absolute; left:110px; top:270px;'>
     <img src="../images/7.png"  onmouseover='checkapp(7)'  id='image_7'   style='position:absolute; left:480px; top:730px;'>
     <img src="../images/8.png"  onmouseover='checkapp(8)'  id='image_8'   style='position:absolute; left:290px; top:440px;'>
     <img src="../images/9.png"  onmouseover='checkapp(9)'  id='image_9'   style='position:absolute; left:625px; top:380px;'>
     <img src="../images/10.png" onmouseover='checkapp(10)' id='image_10'  style='position:absolute; left:410px; top:470px;'>
     <img src="../images/11.png" onmouseover='checkapp(11)' id='image_11'  style='position:absolute; left:570px; top:590px;'>
     <img src="../images/12.png" onmouseover='checkapp(12)' id='image_12'  style='position:absolute; left:360px; top:240px;'>
     <img src="../images/13.png" onmouseover='checkapp(13)' id='image_13'  style='position:absolute; left:680px; top:270px;'>
     <img src="../images/14.png" onmouseover='checkapp(14)' id='image_14'  style='position:absolute; left:225px; top:560px;'>
     <img src="../images/15.png" onmouseover='checkapp(15)' id='image_15'  style='position:absolute; left:700px; top:450px;'>
     <img src="../images/16.png" onmouseover='checkapp(16)' id='image_16'  style='position:absolute; left:80px;  top:440px;'>
     <img src="../images/17.png" onmouseover='checkapp(17)' id='image_17'  style='position:absolute; left:550px; top:450px;'>
     <img src="../images/18.png" onmouseover='checkapp(18)' id='image_18'  style='position:absolute; left:640px; top:680px;'>
     <img src="../images/19.png" onmouseover='checkapp(19)' id='image_19'  style='position:absolute; left:410px; top:695px;'>
     <img src="../images/20.png" onmouseover='checkapp(20)' id='image_20'  style='position:absolute; left:560px; top:720px;'>
     <h5 style='color:#F93; margin-left:40px;'>选择阶梯365的理由</h5>
     <br>
     <ul>
     <li><b class='tag'>更多选择</b><br>数千门精品课程，每天实时发布最新课程，总有一门适合您。</li>
     <li><b class='tag'>更多选择</b><br>数千门精品课程，每天实时发布最新课程，总有一门适合您。</li>
     <li><b class='tag'>品质保证</b><br>我们对全国数万家培训机构的资质和信誉都进行严格的审核。</li>
     <li><b class='tag'>专业服务</b><br>专业的课程评分体制，阶梯365更像您的学习顾问。</li>
     <li><b class='tag'>我们全家都爱学习</b><br>一个账号全家使用，100年的品牌，伴您一生。</li>
     </ul>
     <ul>
     <li><b class='tag'>在线自测</b><br>上完课程您可以在阶梯365网上进行自测，检验您学习课程后的效果。</li>
     <li><b class='tag'>全新体验</b><br>您可以在阶梯试听课程，而且可以申请定制您所需要的课程。</li>
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     </ul>
     <br>
     <img src="./footer.png"/>
     </body>
 </html>

解决方案 »

  1.   

    我把函数稍微改变下
     function checkapp(obj){
                     for (var i=1;i<21,i++)
                     {
                      var s=document.getElementById("image_"+i);
                      var img=document.getElementById("image_"+obj);
                       if(s!==img)
                       {
                       if (s.src=="'../image/'+i+'.png'")
                          s.src='../images/'+i+'.png';
                      }
                     }
                     img.src="../image/"+obj+".png";
                     }
    可还是不行的
      

  2.   

    for (var i=1;i <21,i++)--这是你写错了吧，应该是for(i=1;i<21;i++)；FOR语句你都写错了，程序肯定会错啦 
      

  3.   

    if (s.src=="'../image/'+i+'.png'") ==>
    if (s.src=="../image/"+i+".png")
      

  4.   

    for (var i=1;i <21,i++)  { 
    var s=document.getElementById("image_"+i); 
    if (s.src=="'../image/'+i+'.png'") {
          s.src='../images/'+i+'.png'; 
    alert(s.src);//弹出看看是什么值,如果变化了,可能是你的路径不对.图片太多,我就不测试了
    }
    }
      

  5.   

      function checkapp(obj){
                     for (var i=1;i<21;i++)
                     {
                      var s=document.getElementById("image_"+i);
                      var img=document.getElementById("image_"+obj);
                       if(s!==img)
                       {
                       if (s.src=="../image/"+i+".png")
                          s.src='../images/'+i+'.png';
                      }
                     }
                     img.src="../image/"+obj+".png";
                     }
    函数现在这样还是不行，也就是前面的for循环不起作用
      

  6.   

    for (var i=1;i <21,i++)  { 
    var s=document.getElementById("image_"+i); 
    if (s.src=="'../image/'+i+'.png'") { 
          s.src='../images/'+i+'.png'; 
    alert(s.src);//弹出看看是什么值,如果变化了,可能是你的路径不对.图片太多,我就不测试了 
    } 呵呵添加后显示../images/1.png说明for循环不起作用
      

  7.   

    根本没那么复杂
     <script language="javascript">
                     function checkapp(obj){
                     var img=document.getElementById("image_"+obj);
                     for (var i=1;i<21;i++)
                     {
                      var s=document.getElementById("image_"+i);
                           s.src="../images/"+i+".png";
                     }
                         img.src="../image/"+obj+".png";
                     }
             </script>
    就可以了
      

  8.   

    你去google "js 字符串 相加"