<style>div{font-size:12px;color:red; background-color: #EAEAE8; border: 1 solid #1892B5; padding: 1}</style>
<div id="main1" style="color:blue" onclick="document.all.child1.style.display=(document.all.child1.style.display =='none')?'':'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>
