Move this code inside your onCreate method:
if (bluetooth != null) {
if (bluetooth.isEnabled()) {
String mydeviceaddress = bluetooth.getAddress();
String mydevicename = bluetooth.getName();
status = mydevicename + ":" + mydeviceaddress;
} else {
status = "Bluetooth is not Enabled.";
}
//etc...
Currently this code block is outside of any method of your activity and that is for sure not what you want to have.