Android - Error en botón de llamada

package charly.izquierdofp.es.curso;

import android.content.Intent;

import android.net.Uri;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.EditText;

import android.widget.Toast;

public class TelefonoActivity extends AppCompatActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_telefono);

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        //Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.activity_telefono, 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();

        //noinspection SimplifiableIfStatement

        if (id == R.id.activity_telefono) {

            return true;

        }

        return super.onOptionsItemSelected(item);

    }

    public void PulsaLlamar(View view){

        EditText txtTelefono = (EditText)findViewById(R.id.txtTelefono);

        if(txtTelefono.getText().toString().equals("") || txtTelefono.getText().toString().length()!=9){

            Toast t = Toast.makeText(this,"Error",Toast.LENGTH_SHORT);

            t.show();

        } else {

            Intent i = new Intent(Intent.ACTION_DIAL, Uri.parse("tel:" + txtTelefono.getText().toString()));

            startActivity(i);

        }

    }

}