<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
</head><body>
<div id="main1" style="color:blue" onclick="document.all.child1.style.display=(document.all.child1.style.display =='none')?'block':'none'" >
+ 主目录1</div>
<div id="child1" style="display:none">
        <a href="#">- 子目录1</a> <br>
        <a href="#">- 子目录2</a> <br>
        <a href="#">- 子目录3</a> <br>
        <a href="#">- 子目录4</a> 
</div>
<div id="main2" style="color:blue" onclick="document.all.child2.style.display=(document.all.child2.style.display =='none')?'':'none'" >
+ 主目录2 </div>
<div id="child2" style="display:none; "> 
        <a href="#">- 子目录1</a> <br> 
        <a href="#">- 子目录2</a> <br>
        <a href="#">- 子目录3</a> 
</div>
</body>
</html>

解决方案 »

  1.   

    document.all 在火狐下解释无效
      

  2.   

    直接用    顺便请看看  http://www.vsbing.com  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
    <html xmlns="http://www.w3.org/1999/xhtml"> 
    <head> 
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
    <title>无标题文档 </title> 
    </head> <body> 
    <div id="main1" style="color:blue" onclick="document.all.child1.style.display=(child1.style.display =='none')?'block':'none'" > 
    + 主目录1 </div> 
    <div id="child1" style="display:none"> 
            <a href="#">- 子目录1 </a> <br> 
            <a href="#">- 子目录2 </a> <br> 
            <a href="#">- 子目录3 </a> <br> 
            <a href="#">- 子目录4 </a> 
    </div> 
    <div id="main2" style="color:blue" onclick="document.all.child2.style.display=(child2.style.display =='none')?'':'none'" > 
    + 主目录2 </div> 
    <div id="child2" style="display:none; "> 
            <a href="#">- 子目录1 </a> <br> 
            <a href="#">- 子目录2 </a> <br> 
            <a href="#">- 子目录3 </a> 
    </div> 
    </body> 
    </html> 
      

  3.   

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
    <html xmlns="http://www.w3.org/1999/xhtml"> 
    <head> 
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
    <title>无标题文档 </title> 
    </head> <body> 
    <div id="main1" style="color:blue" onclick="child1.style.display=(child1.style.display =='none')?'block':'none'" > 
    + 主目录1 </div> 
    <div id="child1" style="display:none"> 
            <a href="#">- 子目录1 </a> <br> 
            <a href="#">- 子目录2 </a> <br> 
            <a href="#">- 子目录3 </a> <br> 
            <a href="#">- 子目录4 </a> 
    </div> 
    <div id="main2" style="color:blue" onclick="child2.style.display=(child2.style.display =='none')?'':'none'" > 
    + 主目录2 </div> 
    <div id="child2" style="display:none; "> 
            <a href="#">- 子目录1 </a> <br> 
            <a href="#">- 子目录2 </a> <br> 
            <a href="#">- 子目录3 </a> 
    </div> 
    </body> 
    </html> 
      

  4.   

    4楼的在FF中也不行改成这样就行了<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>无标题文档</title>
    </head>
    <body>
    <div id="main1" style="color:blue" onclick="document.getElementById('child1').style.display=(document.getElementById('child1').style.display =='none')?'block':'none'" >
    + 主目录1</div>
    <div id="child1" style="display:none">
            <a href="#">- 子目录1</a> <br>
            <a href="#">- 子目录2</a> <br>
            <a href="#">- 子目录3</a> <br>
            <a href="#">- 子目录4</a> 
    </div>
    <div id="main2" style="color:blue" onclick="document.getElementById('child2').style.display=(document.getElementById('child2').style.display =='none')?'':'none'" >
    + 主目录2 </div>
    <div id="child2" style="display:none; "> 
            <a href="#">- 子目录1</a> <br> 
            <a href="#">- 子目录2</a> <br>
            <a href="#">- 子目录3</a> 
    </div>
    </body>
    </html>
      

  5.   

    网上说火狐不支持document.all<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
    <html xmlns="http://www.w3.org/1999/xhtml"> 
    <head> 
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
    <title>无标题文档 </title> 
    </head> <body> 
    <div id="main1" style="color:blue" onclick="document.getElementById('child1').style.display=(document.getElementById('child1').style.display =='none')?'block':'none'" > 
    + 主目录1 </div> 
    <div id="child1" style="display:none"> 
            <a href="#">- 子目录1 </a> <br> 
            <a href="#">- 子目录2 </a> <br> 
            <a href="#">- 子目录3 </a> <br> 
            <a href="#">- 子目录4 </a> 
    </div> 
    <div id="main2" style="color:blue" onclick="document.getElementById('child2').style.display=(document.getElementById('child2').style.display =='none')?'':'none'" > 
    + 主目录2 </div> 
    <div id="child2" style="display:none; "> 
            <a href="#">- 子目录1 </a> <br> 
            <a href="#">- 子目录2 </a> <br> 
            <a href="#">- 子目录3 </a> 
    </div> 
    </body> 
    </html>