How to test my android app in all sdk versin of android?

I developed one application in sdk 2.1. Now i want to test this in all sdk version. I trying to test in 2.2 ,1.6,1.5. But all get failed ,all throw exception. what are the changes I need be do in application to work in all sdk?

Please anyone help me to solve this issues.

Thanks

Is your manifest set up to run in all versions of the code you are testing? Try looking at the API documentation on the subject.

just set minsdkVersion in manifest file to 3. than your app will run on 1.5 and 1.6 also.