JS校验文件后缀名

<form id="imgUploadForm" action="/img_upload.html" method="post" enctype="multipart/form-data">
    <input type="hidden" name="id" value="">
    <input id="imgUploadFile" type="file" name="uploadFile"/>
    <input class="button" type="submit" value="上传">
</form>
<script type="text/javascript">
/** JS校验文件后缀名 */
$('#imgUploadForm').submit(function() {
    var filepath = $('#imgUploadFile').val();
    var reg = /(\\+)/g;
    var filename = filepath.replace(reg,"#");
    var one = filename.split("#");
    var two = one[one.length-1];
    var three = two.split(".");
    var last = three[three.length-1];
    var fsuffix = "jpg,gif,png,JPG,GIF,PNG";
    var rs = fsuffix.indexOf(last);
    if(rs>=0){
        return true;
    }else{
        alert("请选择jpg,gif,png格式！");
        return false;
    }                 
});   
</script>

别忘记导入jquery.js