客户端获取下传文件大小

function GetfileSize(addFileuploadCmp) {
    var agent = window.navigator.userAgent;
    var fileSize = 0;
    if (agent.indexOf("Chrome") >= 1) {
            fileSize = addFileuploadCmp.fileInputEl.dom.files[0].fileSize;
        }
       else if (agent.indexOf("Firefox") >= 1) {
            fileSize = addFileuploadCmp.fileInputEl.dom.files[0].fileSize;
        } else if (1==1) { 
//紧紧只是ie
            var fso = new ActiveXObject("Scripting.FileSystemObject");
            fileSize = fso.GetFile(addFileuploadCmp.getValue()).size;
        }
        return fileSize;
};