Android application that doesn't run
<p>I made a simple application that adds 1 to the count and displays the count on a TextView. It compiled and installed fine, but when I run it, a message immediately says "Unfortunately, Counter has stopped."</p>

<pre><code>package com.android.counter;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;


public class CounterActivity extends Activity {
/** Called when the activity is first created. */

private static int count = 0;
Button increment = (Button) findViewById(R.id.inc);
TextView tv = (TextView) findViewById(R.id.CountDisp);


Runnable update = new Runnable()
{
    public void run() {
        increment.setOnClickListener(new View.OnClickListener() 
        {
            public void onClick(View v) 
            {
                count++;
                tv.setText("Count:" + count);
            }
        });
    }
};


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    Thread thr = new Thread(update);
    thr.start();

}

}
</code></pre>
