title: How To Select A Range in an Iframe With "Start" and "End" in Firefox like "selectionStart" from inputs element
body: <p>for Internet Explorer, I have the current code to select a range in an iframe with desingMode setting to on:
     <pre>
      var Range = window.document.selection.createRange();
      var obj = { start: <b>3</b>, end : <b>6</b>}
      Range.collapse( true );
      Range.moveStart( 'character', obj.start );
      Range.moveEnd( 'character', obj.end - obj.start );
      Range.select();</pre></p>
  
  <p>Most useful if I want select only one piece of a string by only 2 parameters. Start and End ( for input elements exists the properties selectionStart and selectionEnd ).</p>
  
  <p>When this code is executed, for example, on a string "Hello World", it highlight only the piece of string <b>llo Wo</b>, or something like that.<br>
  The problem is that Firefox Dom do not support the method moveStart or moveEnd, but only <a href="https://developer.mozilla.org/en/DOM/range.setStart" rel="nofollow noreferrer">range.setStart</a> and range.setEnd which request only a node and an offset as arguments.   </p>
  
  <p>So is possible to virtualizing the moveStart and the moveEnd methods in Firefox?
  Thanks.</p>