（1）读取Built-in
'file -> settings -> Enrionment -> variable type 为 Built-in
os = Environment.Value("OS")
os_version = Environment.Value("OSVersion")
Msgbox os & os_version
（2）设置和读取User-fined
'file -> settings -> Enrionment -> variable type 为 User-fined
'可设置环境变量,自定义登录账户和密码
name = Angent_name , value = mercury
name = Password , value = mercury
Msgbox弹出的是一个可以单击确定关闭的按钮；
print显示的结果在output中显示