Creating a persistent db in Html5 mobile app -

I created a simple Jquery mobile app. A page app that navigates between the divisive app is used to create a simple database, when it launches so that users can register. DB is made after the details of registration users. So the app can be launched next time and DB can be made and can display the home screen if you have registered the user.

But my challenge is that every time I launch the app it refreshes an empty database and rebuilds so I lose the registration details when the user registers. Is there any way i can create a continuous db in jQuery mobile, or whether a user refreshes the app again? My code is below:

  if (window.openDatabase) {// open this database and database db = window.openDatabase ('mydb', '1.0', 'My First database', 2 * 1024 * 1024); }  

In this way I make my DB.

Thanks