为什么向左移动不了？
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.<html xmlns="http://www.
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script type="text/javascript">
function upmove()
{
var startTop=document.getElementById("zfg").style.posTop;
document.getElementById("zfg").style.posTop=startTop-10;
}
function downmove()
{
var startTop1=document.getElementById("zfg").style.posTop;
document.getElementById("zfg").style.posTop=startTop1+10;
}
function rightmove()
{
var startTop2=document.getElementById("zfg").style.posLeft;
document.getElementById("zfg").style.posLeft=startTop2+10;
}
function leftmove()
{
var startTop3=document.getElementById("zfg").style.posLeft;
document.getElementById("zfg").style.posLeft=startTop3-10;
}
function hidemove()
{
var pic=document.getElementById("zfg");
pic.style.display="none";
}
function showmove()
{
var pic=document.getElementById("zfg");
pic.style.display="block";
}
</script>
<style type="text/css">
#css {
background-color: #999;
height: 180px;
width: 200px;
position: absolute;
left: 147px;
top: 80px;
}
-->
</style>
</head>
<body>
<input name="rightmove" type="button" value="向右移动10pt" onclick="rightmove()">
<input name="leftmove" type="button" value="向左移动10pt" onclick="leftmove">
<input name="upmove" type="button" value="上移10pt" onclick="upmove()">
<input name="downmove" type="button" value="下移10pt" onclick="downmove()">
<input name="hidemove" type="button" value="隐藏" onclick="hidemove()">
<input name="showmove" type="button" value="显示" onclick="showmove()">
<FORM> <INPUT TYPE='BUTTON' value='关闭' onClick='window.close()'> </FORM>
<div id="zfg" style="background-color: #999;height: 180px;width: 200px;position: absolute;left: 147px;top: 80px;">可单击上面按钮进行操作</div>
</body>
</html>
