Flash cs4 pro help

programming flash
1

Will when i try to test movie or export it to a movie i get this error

There is no property with the name 'displaystate'.

And here is the src of the error

stop ();
if (!_root.redirectEnabled)
{
    sk._visible = 0;
} // end if
_root.fs.btn_mc.onRelease = function ()
{
    if (Stage.displaystate== "normal")
    {
        Stage.displaystate= "fullScreen";
    }
    else
    {
        Stage.displaystate= "normal";
    } // end else if
};
var listener = {};
listener.onFullScreen = function (isFullscreen)
{
    if (isFullscreen)
    {
        trace ("entered full-screen mode");
    }
    else
    {
        trace ("exited full-screen mode");
    } // end else if
};
Stage.addListener(listener);
_root.setColorMatrix(fs);
_root.setColorMatrix(loader_eff);

Please help me thnx in advance!!