Below code in `onClickLinkToDropbox()` method in `HelloDropboxActivity` class of "Hello Dropbox" example in [Android Sync SDK](https://www.dropbox.com/sh/xiw2rsk3hcjcney/jeDsth_hUD) show error as 

> 
> The type `android.app.Fragment` cannot be resolved. It is indirectly referenced from required `.class` files. 
> 
> 
> 

How can I solve this ? I'm using Android 2.3.3. 

```
mDbxAcctMgr.startLink(this,REQUEST_LINK_TO_DBX);

```