求检测gif,jpg文件类型的正则表达式!!

[haofeng_huang]

请给出完整的脚本，对aaa,aaa.jpg.jpg,aaa.gif.gif等作过滤，a:\image\aaa.jpg,a:\image\aaa.gif则合法。
thx

[fason]

<script>
var s = [
"a:\\image\\aaa.jpg",
"a:\image\aaa.gif.gif",
"a:\\image\\aaa.jpg",
"a:\\image\\aaa"
];

var re = /^.+\\[^\.]+\.(jpg|gif)$/i;
for (var i=0;i<s.length;i++)
document.write(s[i]+":"+re.test(s[i]),"<br/>");
</script>

[bananasmiling]

<script>
var s = [
"a:\\image\\aaa.jpg",
"a:\image\aaa.gif.gif",
"a:\\image\\aaa.jpg",
"a:\\image\\aaa"
];

var re = /^.+\\[^\.]+\.(jpg|gif)$/i;
for (var i=0;i<s.length;i++)
document.write(s[i]+":"+re.test(s[i]),"<br/>");
</script>