Android : Unable to start an activity automatically through "BroadcastReceiver" when device reboots

Just got through Broadcast Receiver and tried to implement it on my app. I want the MainActivity of my app to start automatically when my phone reboots. Now after implementing Broadcast Receiver whole code and setting everything in AndroidMenifest when I restart my phone, it gives an Application error "app_name has stop working".

This is my BootBroadcastReceiver.java class :

public class BootBroadcastReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        // Do your work related to alarm manager
        if (Intent.ACTION_BOOT_COMPLETED.equals(intent.getAction())) {
            Intent serviceIntent = new Intent(context, MainActivity.class);
            serviceIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
            context.startService(serviceIntent);
        }
    }
}

This is my AndroidMenfest.xml :

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.ialarm"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >


<service android:name=".MainActivity" android:label="Main Activity" android:exported="false">
    <intent-filter>
        <action android:name="com.example.ialarm.MainActivity" />
    </intent-filter>
</service>

        <receiver
            android:name=".BootBroadcastReceiver"
            android:enabled="true"
            android:exported="true"
            android:label="BootBroadcastReceiver">

        <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED" />
        </intent-filter>

        </receiver>

        <activity
            android:name="com.example.ialarm.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name="set_alarm_activity" 
                  android:windowSoftInputMode="adjustNothing"
            />
    </application>

</manifest>

I feel there can be some problem with AndroidMenifest, but i set everything according to this stackoverflow question's answers How to start an Application on startup?. I just want to start my MainActivity when my device reboots, please help. Apologies for any mistake.Thanks