title: How to change the font size using execCommand
body: <p>I am having a style for font in my htm file
  <code>FONT{
  font-size:11px;
  }</code>
  which will be loaded initially when my htm loads
  Now I would like to change the font-size using the following command
   <code>document.execCommand("fontsize", "", "5");</code>
  After execution 
  Now the font tag consists of the attribute size = "5"
  But I could see font-size:11px still in Current styles of IE Developer toolbar. So the font is not changed. </p>
  
  <p>How to change the font size
  Please help. </p>