How to dismiss AlertDialog in android

I created AlertDialog that contains 4 buttons

OptionDialog = new AlertDialog.Builder(this);
        OptionDialog.setTitle("Options");
        LayoutInflater li = (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View v = li.inflate(R.layout.options, null, false);
        background = (Button) v.findViewById(R.id.bkgSpinnerLabel);
        SoundVib = (Button) v.findViewById(R.id.SoundVibSpinnerLabel);

        OptionDialog.setView(v);
        OptionDialog.setCancelable(true);
        OptionDialog.setNeutralButton("Ok",
                new DialogInterface.OnClickListener() {

                    public void onClick(DialogInterface arg0, int arg1) {
                    }
                });
        background.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                SetBackground();
             // here I want to dismiss it after SetBackground() method 
            }
        });


        SoundVib.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                Intent soundVibIntent = new Intent(SebhaActivity.this, EditPreferences.class);
                startActivity(soundVibIntent);
            }
        });

        OptionDialog.show();

I want to dismiss it after SetBackground() method, how can I do this? thanks in advance.

Actually there is no any cancel() or dismiss() method from AlertDialog.Builder Class.

So Instead of AlertDialog.Builder optionDialog use AlertDialog instance.

Like,

AlertDialog optionDialog = new AlertDialog.Builder(this).create();

Now, Just call optionDialog.dismiss();

background.setOnClickListener(new OnClickListener() {
    public void onClick(View v) {
        SetBackground();
        // here I want to dismiss it after SetBackground() method 
        optionDialog.dismiss();
    }
});

I think there's a simpler solution: Just use the DialogInterface argument that is passed to the onClick method.

AlertDialog.Builder db = new AlertDialog.Builder(context);
        db.setNegativeButton("cancel", new DialogInterface.OnClickListener(){
            @Override
            public void onClick(DialogInterface d, int arg1) {
                db.cancel();
                //here db.cancel will dismiss the builder

            };  
        });

See, for example, http://www.mkyong.com/android/android-alert-dialog-example.