<script>
var ss="E:\BankUP\Work\Gif\410020.gif";
var l_ss=ss.substring(ss.length-3)
alert (l_ss)
</script>
var ss="E:\BankUP\Work\Gif\410020.gif";
var l_ss=ss.substring(ss.length-3)
alert (l_ss)
</script>
调试欢乐多
b=instr(a,".")+1
filetype=mid(a,b,4)
截取4位主要是怕会出现jpeg这样4位的扩展名出现