在调试的时候，报错说

ReferenceError: Window is not defined

    at Object.<anonymous> (e:\JavaScript\练习\抽奖系统\c.js:6:1)

    at Module._compile (module.js:409:26)

    at Object.Module._extensions..js (module.js:416:10)

    at Module.load (module.js:343:32)

    at Function.Module._load (module.js:300:12)

    at Module.runMain [as _onTimeout] (module.js:441:10)

    at Timer.listOnTimeout (timers.js:92:15)

怎么回事？