Updating Android App on Android App Market

I want to update a Application on Android App Market but the problem is I have开发者_JS百科 a two builds on with the resources for one kind of Devices that is 320x480 and sdk1.5 and another one is for 480x800 and sdk2.1 now how m'I Supposed to do this and How is it Possible. Please Give me some light over this.

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ref - http://osdir.com/ml/Android-Developers/2009-12/msg03004.html

You can use different package name but same manifest label. Not recomended tho