帮忙看看字符串截取时,错误的原因

stringObject.slice(start,end)
start,end必须为数字

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
</head>
<script language="javascript">
var path ="f:\\ss\\aa.txt"
var pathone = path.slice(path.lastIndexOf("\\")+1) ;
alert(pathone);
</script>
<body>
</body>
</html>
IE6下测试通过
var path ="f:\\ss\\aa.txt"
var pathone = path.substr(path.lastIndexOf("\\")+1);
var path ="f:\\ss\\aa.txt";
var pathone = path.substr(path.lastIndexOf("\\")+1);