Android : how to call method when date is set using datepicker in Android

I have created an application in which i have an edit text and a button "show". when the edit text is clicked, date picker pop ups and date can be selected and set to edit text. On clicking the show button, all details on that date will display. This is working. But i need to remove this button "show" and when date is set, automatically details should display ??? how can i do without button onclick ???

datetxt.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int count, int after) {
            // TODO Auto-generated method stub

            }

public void afterTextChanged(Editable s) {

            String temp = datetxt.getText().toString();
            if (s.equals(datetxt)) {

                        "My codes "
     }

This is what i tried.. Its not working.