var type = "IE";	//Variable used to hold the browser name

BrowserSniffer();

//detects the capabilities of the browser
function BrowserSniffer() {
	if (navigator.userAgent.indexOf("Opera")!=-1 && document.getElementById) type="OP";		//Opera
	else if (document.all) type="IE";														//Internet Explorer e.g. IE4 upwards
	else if (document.layers) type="NN";													//Netscape Communicator 4
	else if (!document.all && document.getElementById) type="MO";							//Mozila e.g. Netscape 6 upwards
	else type = "IE";		//I assume it will not get here
}

function showQuiz()
{
    center("quizDiv","overlay");
}

function ShowLayer(id, action){
	if (type=="IE") eval("document.all." + id + ".style.visibility='" + action + "'");
	if (type=="NN") eval("document." + id + ".visibility='" + action + "'");
	if (type=="MO" || type=="OP") eval("document.getElementById('" + id + "').style.visibility='" + action + "'");
}

function DisplayLayer(id, action){
	if (type=="IE") eval("document.all." + id + ".style.display='" + action + "'");
	if (type=="NN") eval("document." + id + ".display='" + action + "'");
	if (type=="MO" || type=="OP") eval("document.getElementById('" + id + "').style.display='" + action + "'");
}

function hideQuiz()
{    
    document.getElementById('overlay').style.display  = 'none';
    ShowLayer("quizDiv","hidden");
}

function center(element,overlay)
{
    var my_width  = 0;
    var my_height = 0;

    if ( typeof( window.innerWidth ) == 'number' )
    {
        my_width  = window.innerWidth;
        my_height = window.innerHeight;
    }
    else if ( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ))
    {
        my_width  = document.documentElement.clientWidth;
        my_height = document.documentElement.clientHeight;
    }
    else if ( document.body && ( document.body.clientWidth || document.body.clientHeight ) )
    {
        my_width  = document.body.clientWidth;
        my_height = document.body.clientHeight;
    }

    //document.getElementById('navBar').style.zIndex  = 97;
    document.getElementById('overlay').style.zIndex = 98;
    document.getElementById('quizDiv').style.zIndex = 99;

    var scrollY = 0;

    if ( document.documentElement && document.documentElement.scrollTop )
    {
        scrollY = document.documentElement.scrollTop;
    }
    else if ( document.body && document.body.scrollTop )
    {
        scrollY = document.body.scrollTop;
    }
    else if ( window.pageYOffset )
    {
        scrollY = window.pageYOffset;
    }
    else if ( window.scrollY )
    {
        scrollY = window.scrollY;
    }

    var overlayHeight = my_height + 300;
    document.getElementById('overlay').style.width = my_width + "px";
    document.getElementById('overlay').style.height = overlayHeight + "px";
    document.getElementById('overlay').style.display = 'block';
    
    
    var setX = 240;//( my_width / 2) - 225;
    var setY = 50;//( my_height / 2) - 125;

    setX = ( setX < 0 ) ? 0 : setX;
    setY = ( setY < 0 ) ? 0 : setY;

    document.getElementById('quizDiv').style.left = setX + "px";
    document.getElementById('quizDiv').style.top = setY + "px";
    //element.style.top  = setY + "px";

    ShowLayer("quizDiv","visible");
}

function resizeQuiz(size)
{
    if (document.getElementById)
    {
        var over = document.getElementById('overlay');
        var quiz = document.getElementById('quizDiv');
    }
    else if(document.layers)
    {
        var over = document.layers['overlay'];
        var quiz = document.layers['quizDiv'];
    }
    else if(document.all)
    {
        var over = document.all['overlay'];
        var quiz = document.all['quizDiv'];
    }
    
    //alert(quiz.style.height);
    quiz.style.height = size + "px";
    //alert(quiz.style.height);
   
}