Eclipse fail to build and run the android App

When first I use to run android project in automatically upload the apk file and run it. It worked for a week. Now when I run a project , the console inform me that the .apk is uploaded and installed but when I run the app. in android emulator , its not the updated one. Any ideas why Eclipse giving this i开发者_如何学Gossue ..

Try to clean a project (Project->Clean) or Try to uninstall App from emulator.

or try to uninstall app from your emulator: settings->applications->manage applications->(your app)->uninstall