OnClickListener error: Source not found
<p>I'm brand new to Android development and right now I am building a simple calculator for healthcare workers. My program implements the OnClickListener class, but every time I click on the button to initiate the calculation, I get an error saying the "Source is not Found".</p>

<p>Here is the code:</p>

<pre><code>public class KidneyeGFR extends Activity implements OnClickListener {
TextView EditAge;
TextView EditSerum;
TextView Gfrtext;
RadioButton Male;
RadioButton Female;
RadioButton EveryoneElse;
RadioButton African;
Button Calculate;
double gender;
double race;
double finalgfr;
private static final int GFRCONST = 186;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    EditAge = (TextView)this.findViewById(R.id.EditAge);
    EditSerum = (TextView)this.findViewById(R.id.EditSerum);

    Male = (RadioButton)this.findViewById(R.id.Male);
    Male.setChecked(true);
    Female = (RadioButton)this.findViewById(R.id.Female);

    EveryoneElse = (RadioButton)this.findViewById(R.id.EveryoneElse);
    EveryoneElse.setChecked(true);
    African = (RadioButton)this.findViewById(R.id.African);

    Calculate = (Button)this.findViewById(R.id.Calculate);
    Calculate.setOnClickListener(this);

}

public void onClick(View v) {
    if (Female.isChecked()) {
        gender = 0.742;
    }
    else {
        gender = 1.0;
    }
    if (African.isChecked()) {
        race = 1.212;
    }
    else {
        race = 1.0;
    }
    calculateGFR();
}


protected void calculateGFR() {
    int age = Integer.parseInt(EditAge.getText().toString());
    double serum = Double.parseDouble(EditSerum.getText().toString());
    finalgfr = GFRCONST * Math.pow(serum, -1.154) * Math.pow(age, -0.203) * gender * race;
    Gfrtext.setText(Double.toString(finalgfr));
}
</code></pre>
