Where do I have to put the event handler?
<p>I have this code for an event handler:</p>

<pre><code>rbM.setOnCheckedChangeListener(new OnCheckedChangeListener() {

            public void onCheckedChanged(CompoundButton buttonView,
                    boolean isChecked) {
                // TODO Auto-generated method stub
                if (isChecked) {
                    try {
                        Double.parseDouble(etAmm.getText().toString());
                        if (etPerc.getText().toString() != null
                                &amp;&amp; etPerc.getText().toString() != "") {
                            etRis.setText(new Double(
                                    Double.parseDouble(etAmm.getText()
                                            .toString()) - percentuale())
                                    .toString());
                            etPercTot.setText(new Double(percentuale())
                                    .toString() + "%");
                        }
                        et30.setText(new Double(Double.parseDouble(etAmm
                                .getText().toString()) - percentuale(30))
                                .toString());
                        etPerc30.setText(new Double(percentuale(30))
                                .toString() + "%");
                        et50.setText(new Double(Double.parseDouble(etAmm
                                .getText().toString()) - percentuale(50))
                                .toString());
                        etPerc50.setText(new Double(percentuale(50))
                                .toString() + "%");
                        et70.setText(new Double(Double.parseDouble(etAmm
                                .getText().toString()) - percentuale(70))
                                .toString());
                        etPerc70.setText(new Double(percentuale(70))
                                .toString() + "%");
                    } catch (Exception ex) {
                    }
                }
            }

        });
</code></pre>

<p>I have it in the onCreate method, but when I start the application it crushes. Why??? Eclipse doesn't give me any error and if I put a try catch block that tries everything in that method I get null as exception. My layout is correct because if I launch the application without any java code edited by me, it loads on the screen perfectly. Help me please!!!!!</p>

<p>p.s.
I have other event handlers but this is the shortest and I don't think it might change from handler to handler, it's always just a declaration.</p>

<p>Here's the logcat as someone asked:</p>

<pre>
03-20 15:03:13.775: D/AndroidRuntime(262): Shutting down VM

03-20 15:03:13.775: W/dalvikvm(262): threadid=1: thread exiting with uncaught exception (group=0x4001d800)

03-20 15:03:13.895: E/AndroidRuntime(262): FATAL EXCEPTION: main

03-20 15:03:13.895: E/AndroidRuntime(262): java.lang.RuntimeException: Unable to start activity ComponentInfo{ciprianis.genius.percentuali/ciprianis.genius.percentuali.PercentualiActivity}: java.lang.NullPointerException

03-20 15:03:13.895: E/AndroidRuntime(262):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)

03-20 15:03:13.895: E/AndroidRuntime(262):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)

03-20 15:03:13.895: E/AndroidRuntime(262):  at android.app.ActivityThread.access$2300(ActivityThread.java:125)

03-20 15:03:13.895: E/AndroidRuntime(262):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)

03-20 15:03:13.895: E/AndroidRuntime(262):  at android.os.Handler.dispatchMessage(Handler.java:99)

03-20 15:03:13.895: E/AndroidRuntime(262):  at android.os.Looper.loop(Looper.java:123)

03-20 15:03:13.895: E/AndroidRuntime(262):  at android.app.ActivityThread.main(ActivityThread.java:4627)

03-20 15:03:13.895: E/AndroidRuntime(262):  at java.lang.reflect.Method.invokeNative(Native Method)

03-20 15:03:13.895: E/AndroidRuntime(262):  at java.lang.reflect.Method.invoke(Method.java:521)

03-20 15:03:13.895: E/AndroidRuntime(262):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)

03-20 15:03:13.895: E/AndroidRuntime(262):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)

03-20 15:03:13.895: E/AndroidRuntime(262):  at dalvik.system.NativeStart.main(Native Method)

03-20 15:03:13.895: E/AndroidRuntime(262): Caused by: java.lang.NullPointerException

03-20 15:03:13.895: E/AndroidRuntime(262):  at ciprianis.genius.percentuali.PercentualiActivity.onCreate(PercentualiActivity.java:62)

03-20 15:03:13.895: E/AndroidRuntime(262):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)

03-20 15:03:13.895: E/AndroidRuntime(262):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)

03-20 15:03:13.895: E/AndroidRuntime(262):  ... 11 more
</pre>
