title: Making a Phone Call with a Number Extension
body: <p>I have code to allow a user to click a button to make a phone call:</p>
  
  <pre><code>public void addCallButton(){
      ImageButton button = (ImageButton) findViewById(R.id.callUsButton);
      button.setOnClickListener(new OnClickListener(){
          public void onClick(View v){
              call01();
          }
      });
  }
  
  private void call01(){
      Intent callIntent = new Intent(Intent.ACTION_DIAL);
      callIntent.setData(Uri.parse("tel:123456789"));
      startActivity(callIntent);
  }
  </code></pre>
  
  <p>However, the number that needs to be dialed is <code>(123)456-789 ex. 123</code></p>
  
  <p>How do I add the extension number in the code?  </p>