Cannot find symbol var showFactButton

public class MainActivity extends AppCompatActivity {
    // Declare our View var
    private TextView mFactTextView;
    private Button mShowFactButton; // this tells me "private feild "mShowFactButton" is assigned but never accessed"


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

        // Assign the Views from the layout file to the corsis var
        mFactTextView = (TextView) findViewById(R.id.factTextView);
        mShowFactButton = (Button) findViewById(R.id.showFactButtton); // This tells me "Cannot find symbol showFactButton"

        View.OnClickListener listener = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String[] facts = {
                        "Butterflies cannot fly if their body temperature is less than 86 degrees.",
                        "Neurons multiply at a rate 250,000 neurons per minute during early pregnancy.",
                        "Elephants have the longest pregnancy in the animal kingdom at 22 months. The longest human pregnancy on record is 17 months, 11 days.",
                        "Flies jump backwards during takeoff.",
                        "The human brain is about 75% water.",
                        "A housefly will regurgitate its food and eat it again.",
                        "Termites outweigh humans by almost ten to one.",
                        "It is impossible to lick your elbow.",
                        "Intelligent people have more zinc and copper in their hair.",
                        "In every episode of Seinfeld there is a Superman somewhere.",
                        "Wearing headphones for just an hour will increase the bacteria in your ear by 700 times.",
                        "This app was made via treehouse."

                };


                String fact = "";
                // Randomly select a fact.
                Random randomGenerator = new Random();
                int randomNumber = randomGenerator.nextInt(facts.length);
                fact = facts[randomNumber];

                // Update the screen with our dynamic fact.
                mFactTextView.setText(fact);
            }
        };
    }
}