Popup with call email and sms function

Question

I am a beginner in android app development.. i have made an app now and there is a pop up in it which shows a persons name and details.. i have added 3 buttons there like CALL,SMS,EMAIL.. i went for call activity, but its not working. no error is there still call button is not making calls.. The same code i have tried in a new project, there it works well.. but when i do it on that popup, call is not working... please help me

public class popupinv extends AppCompatActivity {

    public Button b;
    public void init(){
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_popupinv);
        init();

        b= (Button) findViewById(R.id.call);

        b.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent callIntent=new Intent(Intent.ACTION_CALL);
                callIntent.setData(Uri.parse("tel:123456));
                startActivity(callIntent);

            }
        });
    }
}