Code:
function resizeSite(textObj, buttonObjSeand, buttonObjClear, closeObjSeand, closeObjClear)
{
    var _loc1 = {};
    closeObjSeand._visible = false;
    closeObjClear._visible = false;
    titleTextInfo = "Exit full-screen mode (Esc) to enter text";
    titleTextButton = "Exit full-screen mode (Esc) to send the form";
    _loc1.onFullScreen = function (isFullscreen)
    {
        if (isFullscreen)
        {
            textObj.htmlText = titleTextInfo;
            buttonObj.useHandCursor = false;
            closeObjSeand._visible = true;
            closeObjSeand._x = buttonObjSeand._x;
            closeObjSeand._y = buttonObjSeand._y;
            closeObjSeand._width = buttonObjSeand._width + 5;
            closeObjSeand._height = buttonObjSeand._height + 5;
            closeObjClear._visible = true;
            closeObjClear._x = buttonObjClear._x;
            closeObjClear._y = buttonObjClear._y;
            closeObjClear._width = buttonObjClear._width + 5;
            closeObjClear._height = buttonObjClear._height + 5;
            closeObjClear.onRelease = function ()
            {
                textObj.htmlText = titleTextButton;
            };
            closeObjSeand.onRelease = function ()
            {
                textObj.htmlText = titleTextButton;
            };
        }
        else
        {
            closeObjSeand.useHandCursor = true;
            textObj.htmlText = " ";
            closeObjSeand._visible = false;
            closeObjClear._visible = false;
        } // end else if
    };
    if (Stage.displayState == "fullScreen")
    {
        textObj.htmlText = titleTextInfo;
        buttonObj.useHandCursor = false;
        closeObjSeand._visible = true;
        closeObjSeand._x = buttonObjSeand._x;
        closeObjSeand._y = buttonObjSeand._y;
        closeObjSeand._width = buttonObjSeand._width + 5;
        closeObjSeand._height = buttonObjSeand._height + 5;
        closeObjClear._visible = true;
        closeObjClear._x = buttonObjClear._x;
        closeObjClear._y = buttonObjClear._y;
        closeObjClear._width = buttonObjClear._width + 5;
        closeObjClear._height = buttonObjClear._height + 5;
        closeObjClear.onRelease = function ()
        {
            textObj.htmlText = titleTextButton;
        };
        closeObjSeand.onRelease = function ()
        {
            textObj.htmlText = titleTextButton;
        };
    } // end if
    Stage.addListener(_loc1);
} // End of the function

Code:

_root.btn_mc.onRelease = function ()
{
    if (Stage.displayState == "normal")
    {
        Stage.displayState = "fullScreen";
    }
    else
    {
        Stage.displayState = "normal";
    } // end else if
};
_root.btn_mc.onRollOver = function ()
{
    _root.btn_mc.gotoAndPlay("s1");
};
_root.btn_mc.onRollOut = _root.btn_mc.onReleaseOutside = function ()
{
    _root.btn_mc.gotoAndPlay("s2");
};
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);