phonegap iphone : Documents Directory Absolute path

I am new to PhoneGap and I am using it with Xcod开发者_开发知识库e.

Can anybody tell me how to get to the absolute path of the Documents Directory in the index.html?

function success(fileSystem) {
    var path = fileSystem.root.fullPath;
}

// request the persistent file system
window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, success, null);

path should point to /Documents.