Flash fullscreen working in Firefox not in IE!

Can anyone please tell me why the following code works for Firforx but not for IE? Both the Firefox and IE have flash player version [COLOR=Magenta]**9,0,47,0

**[/COLOR]

function goFullScreen()
{    
    Stage['displayState'] = 'fullScreen';    
}

function offFullScreen()
{
    Stage['displayState'] = 'normal';
}

btn_GoFullScreen.onRelease = goFullScreen;
btn_GoNormalScreen.onRelease = offFullScreen;

I hv also included the **[COLOR=Magenta]allowFullscreen=“true” [/COLOR]**code in the object/embed tags in the html. But still it works for Firfox only but not for IE.

Does the fullscreen functionality require some specific settings/updates for browser also?