java - Unfortunately my app has stopped in Android Emulator

I've been looking for an answer for hours now, but my calculator wont work at all :(

I appreciate if you could help me. I've posted the manifest code below. Inform me if you need to see the MainActivity.java or anything else :)

    
package="com.example.elof_calc_2000_dragonslayerxx"
android:versionCode="1"
android:versionName="1.0" >

     android:minSdkVersion="15"
    android:targetSdkVersion="17" />

     android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
         android:name="com.example.elof_calc_2000_dragonslayerxx.MainActivity"
        android:label="@string/app_name" >
        
            

            
        
    
 

The errors shown on Logcat

03-16 18:09:59.890: E/AndroidRuntime(895): FATAL EXCEPTION: main
03-16 18:09:59.890: E/AndroidRuntime(895): Process: com.example.elof_calc_2000_dragonslayerxx,     PID: 895
03-16 18:09:59.890: E/AndroidRuntime(895): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.elof_calc_2000_dragonslayerxx/com.example.elof_calc_2000_dragonslayerxx.MainActivity}: java.lang.NullPointerException
03-16 18:09:59.890: E/AndroidRuntime(895):  at  android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.ActivityThread.access$800(ActivityThread.java:135)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.os.Handler.dispatchMessage(Handler.java:102)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.os.Looper.loop(Looper.java:136)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.ActivityThread.main(ActivityThread.java:5017)
03-16 18:09:59.890: E/AndroidRuntime(895):  at java.lang.reflect.Method.invokeNative(Native Method)
03-16 18:09:59.890: E/AndroidRuntime(895):  at java.lang.reflect.Method.invoke(Method.java:515)
03-16 18:09:59.890: E/AndroidRuntime(895):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
03-16 18:09:59.890: E/AndroidRuntime(895):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
03-16 18:09:59.890: E/AndroidRuntime(895):  at dalvik.system.NativeStart.main(Native Method)
03-16 18:09:59.890: E/AndroidRuntime(895): Caused by: java.lang.NullPointerException
03-16 18:09:59.890: E/AndroidRuntime(895):  at com.example.elof_calc_2000_dragonslayerxx.MainActivity.onClickListeners(MainActivity.java:49)
03-16 18:09:59.890: E/AndroidRuntime(895):  at com.example.elof_calc_2000_dragonslayerxx.MainActivity.onCreate(MainActivity.java:22)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.Activity.performCreate(Activity.java:5231)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
03-16 18:09:59.890: E/AndroidRuntime(895):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
03-16 18:09:59.890: E/AndroidRuntime(895):  ... 11 more
03-16 18:16:23.316: E/AndroidRuntime(1100): FATAL EXCEPTION: main
03-16 18:16:23.316: E/AndroidRuntime(1100): Process: com.example.elof_calc_2000_dragonslayerxx, PID: 1100
03-16 18:16:23.316: E/AndroidRuntime(1100): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.elof_calc_2000_dragonslayerxx/com.example.elof_calc_2000_dragonslayerxx.MainActivity}: java.lang.NullPointerException
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.os.Handler.dispatchMessage(Handler.java:102)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.os.Looper.loop(Looper.java:136)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.ActivityThread.main(ActivityThread.java:5017)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at java.lang.reflect.Method.invokeNative(Native Method)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at java.lang.reflect.Method.invoke(Method.java:515)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at dalvik.system.NativeStart.main(Native Method)
03-16 18:16:23.316: E/AndroidRuntime(1100): Caused by: java.lang.NullPointerException
03-16 18:16:23.316: E/AndroidRuntime(1100):     at com.example.elof_calc_2000_dragonslayerxx.MainActivity.onClickListeners(MainActivity.java:49)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at com.example.elof_calc_2000_dragonslayerxx.MainActivity.onCreate(MainActivity.java:22)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.Activity.performCreate(Activity.java:5231)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
03-16 18:16:23.316: E/AndroidRuntime(1100):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
03-16 18:16:23.316: E/AndroidRuntime(1100):     ... 11 more

Answer

Here are your key lines

03-16 18:16:23.316: E/AndroidRuntime(1100): Caused by: java.lang.NullPointerException
03-16 18:16:23.316: E/AndroidRuntime(1100):     at com.example.elof_calc_2000_dragonslayerxx.MainActivity.onClickListeners(MainActivity.java:49)

You have a NullPointerException on line 49 of your MainActivity. You can post that for further help. Whatever code is there ensure that it is initialized (and thus not null) before you call it.