Create checkbox in a specific section of the page in Android

In my Android application, I have created a static list of checkboxes in xml. On click of a button, I am trying to create a new checkbox after the static checkbox.

But all the time, when i click the button, a new checkbox gets created in the top left corner. How to dynamically create the button after an already existing checkbox.

btnAdd.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            try {
                ActionBar.LayoutParams params = new ActionBar.LayoutParams(ActionBar.LayoutParams.WRAP_CONTENT, ActionBar.LayoutParams.WRAP_CONTENT);
                CheckBox cb = new CheckBox(caseSheetForm.this);
                cb.setLayoutParams(params);
                cb.setText("New Checkbox");
                RelativeLayout rl = (RelativeLayout) findViewById(R.id.relativelayout);
                rl.addView(cb);
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    });