require('express')报错，怎么回事呀

D:\softwear\nodeJS\node_global\express:4 case uname in ^^^^

SyntaxError: Unexpected token case at exports.runInThisContext (vm.js:53:16) at Module._compile (module.js:413:25) at Object.Module._extensions..js (module.js:452:10) at Module.load (module.js:355:32) at Function.Module._load (module.js:310:12) at Module.require (module.js:365:17) at require (module.js:384:17) at Object. (G:\noteBook\nodeJS\mydemo\index.js:28:17) at Module._compile (module.js:434:26) at Object.Module._extensions..js (module.js:452:10)