title: DefaultTextFormat vs SetTextFormat
body: <p>here are 2 code blocks. </p>
  
  <pre><code>var myTextField:TextField = new TextField();
  var myTextFormat:TextFormat = new TextFormat();
  
  addChild(myTextField);
  
  myTextFormat.font = "Arial";
  myTextFormat.size = 15;
  myTextFormat.color = 0x0000FF;
  
  myTextField.text = "some text";
  **myTextField.setTextFormat(myTextFormat);**
  </code></pre>
  
  <p>VS </p>
  
  <pre><code>var myTextField:TextField = new TextField();
  var myTextFormat:TextFormat = new TextFormat();
  
  addChild(myTextField);
  
  myTextFormat.font = "Arial";
  myTextFormat.size = 15;
  myTextFormat.color = 0x0000FF;
  
  **myTextField.defaultTextFormat = myTextFormat;**
  </code></pre>
  
  <p>So , What's the difference between 
  setTextFormat() and defaultTextFormat ? Why two different ways ( one by property another by method) to do things. </p>
  
  <p>Tested with some more code : </p>
  
  <pre><code>var my_txt:TextField =new TextField();
      my_txt.type = TextFieldType.INPUT
       var my_fmt:TextFormat = new TextFormat();
       my_fmt.color = 0xFF0000;
  
       my_txt.text = "this is for setTextFormat with range";
       my_txt.setTextFormat(my_fmt,0,3);
  
      // my_txt.text = "this is for setTextFormat without range";
      // my_txt.setTextFormat(my_fmt);
  
      // my_txt.defaultTextFormat = my_fmt;
      // my_txt.text = "this is for default text format";
  
      addChild(my_txt);
  </code></pre>
  
  <p>V.</p>