Unable to create Android apps for version 2.1

I'm new to writing android apps. I installed JDK, and the eclipse Android plugin. I've written a simple Hello World app, but I can only make it in Android versions 2.3.1, 2.3.3, 3.0, and 3.1. I'm using a Sprint Samsung Galaxy and I think thats version 2.1.

When I try to run the program on my phone, Eclipse can't find it. I've enabled Unkno开发者_如何学Pythonwn Sources and USB debugging on my phone.

Any suggestions?

First try the helloworld in the emulator, then close the emulator. Restart your computer and install the debug drivers for your phone. Find them in the manufacturer's site. Then put your phone in charge only. If it doesn't work, try the other modes. Be aware that it doesn't get the connection instantly, it may take some minutes but not more. Be patient.

Have you installed the USB driver for your phone?