function show_quiz()
{
  //achtergrond
  $(document.createElement('div')).attr('id','quizbg').appendTo('body');

  //Placeholder voor quiz panel
  var quizholderobj=$(document.createElement('div')).attr('id','quizholder').appendTo('body');

  $(quizholderobj).load('http://www.doegroendatscheelt.nl/view.quiz.html',function(){

    //1e vraag ophalen
    show_quiz_question(0,-1,-1);

    $('#quizbg,#quizholder').fadeIn();

  });
}


function closeQuiz()
{
  $('#quizbg,#quizholder').remove();
}


function submit_quiz(do_next)
{
  var cur_question=parseInt($('#quizform > fieldset.question').attr('id').replace(/([^0-9])/g,''));

  var selectedAnswer=-1;
  $('#quizform > fieldset.question > input[name="answer"]').each(function(i){
    if($(this).attr('checked')) selectedAnswer=i;
  });

  var next_question=cur_question+1;
  if(!do_next && cur_question>0) next_question=cur_question-1;

  show_quiz_question(next_question,cur_question,selectedAnswer);

  return false;
}



function show_quiz_question(next_question,current_question,current_anwer)
{

  $('#quizform > fieldset.question, #prev_question, #next_question').hide();
  $('#loadquiz_ani').show();

   var pushStr=new Date().getTime();

    $.getJSON('http://www.doegroendatscheelt.nl/show.quiz.json?q='+next_question+'&cq='+current_question+'&ca='+current_anwer+'&push='+pushStr,function(data){

    $('#loadquiz_ani').hide();

    if(data.success)
    {
      if(data.finished)
      {

        $('#quizform').remove();
        $('#quiz').addClass('finish');

        $('#quizinfo').html('<h1>'+data.title+' <span>'+data.score+'</span></h1><div>'+data.description+'</div>');

      }
      else
      {

        questionHtml ='<span class="questionnr">'+(parseInt(data.nr)+1)+'</span>';
        questionHtml+='<strong>'+data.question+'</strong>';

        for(var a=0;a<data.options.length;a++)
        {
          if(data.answer_index==a)
          {
            questionHtml+='<input type="radio" id="answer'+a+'" name="answer" checked="true" value="'+a+'" />';
          }
          else
          {
            questionHtml+='<input type="radio" id="answer'+a+'" name="answer" value="'+a+'" />';
          }
          questionHtml+='<label for="answer'+a+'"> '+data.options[a]+'</label>';
          questionHtml+='<br style="clear:both;" />';
        }

        $('#quizform > fieldset.question').attr('id','question'+(data.nr)).html(questionHtml);

	$('#quizform > fieldset.question').show();

        if(data.nr>0) $('#prev_question').show();
        if(data.nr<data.total) $('#next_question').show();
      }

    }
    else
    {
      alert('Fout bij ophalen van de vraag');
    }
   });

}