pack error with google chrome extention

My exte开发者_如何学Gonsion works well under the dev mode,but when i want to pack it this time ,there comes an error which said:"Manifest file missing or unreadable", i don't know why!

{
"name": "DoTask",
"version": "1.0",
"description": "DoTaskv2个人任务管理系统--谷歌浏览器插件",
"options_page": "option.html",
"icons": { "16": "favicon.ico", "32": "favicon.ico", "128": "favicon.ico"},
"browser_action": {
"default_icon": "favicon.ico",
    "popup": "popup.html"
    },
"permissions": [
     "http://*/*"
    ]
}

The manifest file must be named manifest.json (notice: json not js), must be in the root of the zip file or directory and it also must be saved as UTF-8.