title: Checking radio group either empty/null
body: <p>I want to check in android  that radiogroup is empty or null i.e submitted without clicking on any radio button in that group??</p>
  
  <p><strong>Xml Code</strong></p>
  
  <pre><code>&lt;RadioGroup
              android:id="@+id/lift"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="horizontal" &gt;
  
              &lt;RadioButton  
                  android:paddingRight="50dip"  
                  android:textSize="20dp"  
                  android:id="@+id/r91"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:text="@string/yes" /&gt;
  
              &lt;RadioButton   
                  android:paddingRight="50dip"   
                  android:textSize="20dp"  
                  android:id="@+id/r92"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:text="@string/no" /&gt;
          &lt;/RadioGroup&gt;
  </code></pre>
  
  <p><strong>Activity Code</strong></p>
  
  <pre><code>RadioGroup radioGroup1 = (RadioGroup) findViewById(R.id.lift);
  if(radioGroup1=='NULL')
  { 
      Toast.makeText(getApplOicationContext(),"first radiogroup is null",Toast.LENGTH_LONG).show();
  }
  </code></pre>