Run some code when user update my app
<p>I would like to upgrade my app to android market. and some users have the old version of the app. What i want to do is in my new app, i want to run some codes to change a bit on the app database when the user do the update of my app, so how can i check if the user has the older version of my app in their mobile?</p>

<p>would appreciate any feedbacks !! thanks a lot!</p>

<p>regards
justin</p>
