(function(){
//将命名空间IC注册到window
window['JSHide']={};
//隐藏侧边栏，并将图片换成右箭头图片
function yc()
{
document.getElementById("cloone").style.display ="none";
document.getElementById("img").innerHTML ="<img src='Image/右箭头.png' width='10' height='10' longdesc='Image/右箭头.png' onclick='JSHide.xs()' />";
}
window['JSHide']['yc']=yc;
//显示侧边栏，并将图片换成左箭头
function xs()
{
document.getElementById("cloone").style.display ="";
document.getElementById("img").innerHTML ="<img src='Image/左箭头.png' width='10' height='10' longdesc='Image/左箭头.png' onclick='JSHide.yc()' />";
}
window['JSHide']['xs']=xs;
})();
<!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=gb2312" />
<title>javascript分栏模式</title>
<script language="JavaScript" type="text/javascript" src="JS/JSHide.js"></script>
</head>
<body>
<table width="425" height="198" border="1">
<tr>
<td id="cloone" width="55" align="center" valign="middle" scope="row">
<p><a href="if测试.html" target="_blank">栏目一</a></p>
<p><a href="for循环.html" target="_blank">栏目二</a></p>
<p><a href="CSS初步变色消失出现.html" target="_blank">栏目三</a></p>
<p><a href="1加到100.html" target="_blank">栏目四</a></p>
<p><a href="JS初步.html" target="_blank">栏目五</a></p>
</td>
<td width="102" align="center" valign="middle">
<span id="img">
<img src="Image/左箭头.png" width="10" height="20" longdesc="Image/左箭头.png" onclick="JSHide.yc()"/>
</span>
</td>
<td width="71" align="center" valign="middle">这里是内容区域</td>
<td width="169" align="center" valign="middle"><input type="text" name="textfield" id="txtid" value="yesle" /></td>
</tr>
</table>
</body>
</html>