javascript

function filefujianChange(target) {
    var fileSize = 0;
    var bro=$.browser;
    var binfo="";
    if(bro.msie){
        var isIE = true;
    }
    if (isIE && !target.files) {
        var filePath = target.value;
        var fileSystem = new ActiveXObject("Scripting.FileSystemObject");
        var file = fileSystem.GetFile (filePath);
        fileSize = file.Size;
    } else {
        fileSize = target.files[0].size;
    }
    var size = fileSize / 1024;
    //这里限制大小
    if(size>2000){    
        alert("附件不能大于2M");
        target.value="";
        return
    }
    var name=target.value;
    var fileName = name.substring(name.lastIndexOf(".")+1).toLowerCase();
    //这里限制类型
    if(fileName !="pdf" && fileName !="ppt"){       
        alert("请选择PPT或PDF格式文档！");
        target.value="";
        return
    }
}

html

<input type="file" onchange="filefujianChange(this);" />