一个简单的折叠打开的例子!

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
 <head>
  <title></title>
  <meta name="GENERATOR" content="Microsoft Visual Studio .NET 7.1">
  <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
<script language=javascript>
function b1_onclick()
{
    if(b1.innerText=="+")
     {
   list1.style.display="block";
      b1.innerText="-";
     }

else if(b1.innerText=="-")
{
   list1.style.display="none";
   b1.innerText="+";
  
}
}
</script>
</head>
 <body>
  <span id=b1 style="BORDER-RIGHT: thin ridge; BORDER-TOP: thin ridge; BORDER-LEFT: thin ridge; CURSOR: hand; BORDER-BOTTOM: thin ridge; BODER: thin" language=javascript onclick="b1_onclick()">-</span>list1<br>//注意用SPAN给控制住
  <ul id=list1>//注意想要在JS上控制,必须有个ID才行
  <li><FONT face="宋体">item1</FONT></li>
  <li><FONT face="宋体">item2</FONT></li>
  <li><FONT face="宋体">item3</FONT></li>
  </ul>
  <P><FONT face="宋体">list2</FONT></P>
 </body>
</html>

原文地址:https://www.cnblogs.com/Dreamfly/p/433542.html