Android : How to add a reset button to clear numbers on Edittext field

I want to add a button to clear the numbers on textfield by tapping on the button.

(Reset my EditText back to an empty "space" after a button has pressed that would have completed an activity with input from the EditText field.)

Cheers! Thanks!

ActivityMain XML file!

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/back"
    android:orientation="vertical"
    tools:context="com.miuapps.unitconverter.Centimetres_Metres" >

    <TextView
        android:id="@+id/textView1"    //first textview
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Enter a Value(cm) :"
        android:layout_gravity="center"
        android:gravity="center"
        android:textSize="30dp"/>

    <EditText
        android:id="@+id/editText1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:inputType="number" />

    <Button
        android:id="@+id/button1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="Convert" />

    <TextView
        android:id="@+id/tvDisplay1"   //output textview
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="In Metres: 0"
        android:textSize="30dp" />

</LinearLayout>

---

double counter, counter2 = 100;
    double x;
    Button conv;
    TextView dis1, dis2;
    EditText ent1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        counter = 0;

        conv = (Button)findViewById(R.id.button1);
        dis1 = (TextView)findViewById(R.id.tvDisplay1);
        //dis2 = (TextView)findViewById(R.id.tvDisplay2);
        ent1 = (EditText)findViewById(R.id.editText1);

        conv.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                x = new Integer(ent1.getText().toString());
                counter = x/100;
                //counter2++;
                dis1.setText("In Metres: " +counter);
                //dis2.setText("In Centimetres: " +counter2);
            }
    });  
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}