function showHide(elementid) {
    if (document.getElementById(elementid).style.display == 'none') {
        document.getElementById(elementid).style.display = '';
    } else {
        document.getElementById(elementid).style.display = 'none';
    }
}

function setMenuStyle(elementId) {
    if (elementId != null) {
        var a = elementId.parentElement.parentElement;
        for (var i = 0; i < a.childNodes.length; ++i) {
            a.childNodes[i].className = '';
        }
        elementId.parentElement.className = 'mainNavSelected';
    }
}

function switchTab(elementId) {
    document.getElementById('tabSingleContent').style.display = 'none';
    document.getElementById('tabMultiContent').style.display = 'none';
    document.getElementById('tabTriviaContent').style.display = 'none';

    document.getElementById('tabSingle').style.borderRight = "0px solid #cdcdcd";
    document.getElementById('tabSingle').style.borderLeft = "0px solid #cdcdcd";

    document.getElementById('tabMulti').style.borderRight = "0px solid #cdcdcd";
    document.getElementById('tabMulti').style.borderLeft = "0px solid #cdcdcd";

    document.getElementById('tabTrivia').style.borderRight = "0px solid #cdcdcd";
    document.getElementById('tabTrivia').style.borderLeft = "0px solid #cdcdcd";

    switch (elementId.id) {
        case "tabSingle":
            document.getElementById('tabSingle').className = 'active';
            document.getElementById('tabMulti').className = '';
            document.getElementById('tabTrivia').className = '';
            document.getElementById('tabSingle').style.borderRight = "1px solid #cdcdcd";
            showHide('tabSingleContent');
            break;
        case "tabMulti":
            document.getElementById('tabSingle').className = '';
            document.getElementById('tabMulti').className = 'active';
            document.getElementById('tabTrivia').className = '';
            document.getElementById('tabMulti').style.borderRight = "1px solid #cdcdcd";
            document.getElementById('tabMulti').style.borderLeft = "1px solid #cdcdcd";
            showHide('tabMultiContent');
            break;
        case "tabTrivia":
            document.getElementById('tabSingle').className = '';
            document.getElementById('tabMulti').className = '';
            document.getElementById('tabTrivia').className = 'active';
            document.getElementById('tabMulti').style.borderLeft = "1px solid #cdcdcd";
            showHide('tabTriviaContent');
            break;
    }
}

//                                    $('#lifreequizzes').click(function(event){
//                                    var k=1;
//                                    if ($('#plpl').size()>0) { k=0; }
//                                    var oldBlocks = $('.chapterBlock').slideUp('normal',function(){oldBlocks.remove();});
//                                    if (k==0) { return true; }
//                                      var target = this;
//                                      var folder = this.id;
//                                      var block = $('<div id="plpl"></div>');
//                                      block.append('<div><a href="webquiz.aspx?topic=0">Random Questions</a></div>');            
//                                      block.append('<div><a href="webquiz.aspx?topic=2">History quiz</a></div>');            
//                                      block.append('<div><a href="webquiz.aspx?topic=3">Sports Quiz</a></div>');            
//                                      block.append('<div><a href="webquiz.aspx?topic=4">Literature Quiz</a></div>');            
//                                      block.append('<div><a href="webquiz.aspx?topic=5">People&Celebrities Quiz</a></div>');            
//                                      block.append('<div><a href="webquiz.aspx?topic=6">Geography quiz</a></div>');            
//                                      block.append('<div><a href="webquiz.aspx?topic=7">Arts Quiz</a></div>');            
//                                      block.append('<div><a href="webquiz.aspx?topic=8">TV Quiz</a></div>');            
//                                      block.append('<div><a href="webquiz.aspx?topic=9">Science&Technology Quiz</a></div>');            
//                                      block.append('<div><a href="webquiz.aspx?topic=10">Movie Quiz</a></div>');            
//                                      block.append('<div><a href="webquiz.aspx?topic=11">Music Quiz</a></div>');            
//                                      block.append('<div><a href="webquiz.aspx?topic=12">Entertainment Quiz</a></div>');                                                                   
//                                      block.append('<div><a href="singleplayer.aspx">more quizzes...</a></div>');                                                                   
//                                      block.css('display','none').addClass('chapterBlock').appendTo(target).slideDown();                                      
//                                      })