function decrement_field(field_id)
{
  var field = document.getElementById(field_id);
  field.value = parseInt(field.value) - 1;
  check_number_field(field);
}

function check_number_field(field)
{
  if (isNaN(field.value)) {
    field.value = 0;
  }
  if (parseInt(field.value) <= 0) {
    field.value = 0;
  }
}

function increment_field(field_id)
{
  var field = document.getElementById(field_id);
  field.value = parseInt(field.value) + 1;
  check_number_field(field);
}

function set_image(image_name, element)
{
  var div_element = document.getElementById(element);
  div_element.style.setProperty('background-image', 'url(tl_files/aero_imgs/'+image_name+')', '');
}

function switch_subimage(element, image_count)
{
  var div_element   = document.getElementById(element);
  var height        = div_element.offsetHeight;
  var image_offset  = height * (image_count-1);
  div_element.style.backgroundPosition ='0 '+image_offset+'px';
}

function teaser_switch_activate_trainer(button_div, image_div, arrow_div)
{
  switch_subimage(button_div,4);
  switch_subimage(image_div,2);
  var text_target = document.getElementById(image_div);
  removeChildren(text_target);
  var heading_text = 'Der aeroman<sup>&reg;</sup> für Trainer und Leistungsdiagnostiker';
  var main_text     = 'Der neue Fitness-Check für ein effizientes Cardio-Training ist da! Nach maximal 10 Minuten erhalten Sie Informationen, mit denen Ihre Kunden ihr Cardio-Training individuell optimieren können.';
  var arrow_link   = '/index.php/aeroman_sportmedic';
  teaser_switch_generate_text(text_target, heading_text, main_text, arrow_link);
  var arrow       = document.getElementById(arrow_div);
  arrow.style.display = 'block';
  arrow.style.left = '0%';
}

function teaser_switch_activate_fitness(button_div, image_div, arrow_div)
{
  switch_subimage(button_div,3);
  switch_subimage(image_div,2);
  var text_target = document.getElementById(image_div);
  removeChildren(text_target);
  var heading_text  = 'Der aeroman<sup>&reg;</sup> für Fitness-Studios';
  var main_text    = 'Der neue Ausdauer-Check ist da! Nach maximal 10 Minuten erhalten Sie Informationen, mit denen Sie das Training Ihres Sportlers individuell optimieren können.';
  var arrow_link    = '/index.php/aeroman_fitness';
  teaser_switch_generate_text(text_target, heading_text, main_text, arrow_link);
  var arrow       = document.getElementById(arrow_div);
  arrow.style.display = 'block';
  arrow.style.left = '33%';
}

function teaser_switch_activate_reha(button_div, image_div, arrow_div)
{
  switch_subimage(button_div,2);
  switch_subimage(image_div,2);
  var text_target = document.getElementById(image_div);
  var heading_text  = 'Der aeroman<sup>&reg;</sup> für Sport- und Physiotherapeuten';
  var main_text     = 'Der neue Ausdauer-Test für Reha und Therapie ist da! Nach maximal 10 Minuten erhalten Sie Informationen, mit denen Sie die Maßnahmen zur effizienten Wiedergewinnung der Ausdauerleistungsfähigkeit optimieren können.';
  var arrow_link   = '/index.php/aeroman_reha';
  removeChildren(text_target);
  teaser_switch_generate_text(text_target, heading_text, main_text, arrow_link);
  var arrow       = document.getElementById(arrow_div);
  arrow.style.display = 'block';
  arrow.style.left = '66%';
}

function teaser_switch_generate_text(text_target, heading_text, main_text, arrow_link)
{
  removeChildren(text_target);
  var heading = createH1(false, heading_text);
  heading.style.color       = '#ffffff';
  heading.style.marginLeft  = '30px';
  heading.style.marginTop   = '0px';
  heading.style.paddingTop  = '30px';
  text_target.appendChild(heading);
  var text = createP(false, main_text);
  text.style.marginLeft     = '30px';
  text.style.color          = '#ffffff';
  text.style.width       = '400px';
  text_target.appendChild(text);
  if (arrow_link) {
    var link = (
      createLink(
        arrow_link,
        ''
      )
    );
    link.appendChild(
      createImage(
        'tl_files/aero_imgs/buttons/arrow_white_horizontal.png',
        'zur aeroscan-Seite'
      )
    );
    link.style.marginLeft     = '30px';
    text_target.appendChild(link);
  }
  return text;
}

function teaser_checked_reset(
  event,
  parent_id,
  button_div,
  image_div,
  arrow_div
) {
  if(check_event_origin(event, parent_id)) {
    switch_subimage(button_div,1);
    switch_subimage(image_div,1);
    var text_target     = document.getElementById(image_div);
    var heading_text    = 'aeroman<sup>&reg;</sup> professional';
    var main_text       = 'Mit dem aeroman<sup>&reg;</sup> professional beantworten Sie die spezifischen Fragestellungen Ihrer<br /> Kunden.  ';
    var arrow_link      = false;
    removeChildren(text_target);
    var text            = teaser_switch_generate_text(text_target, heading_text, main_text, arrow_link);
    var arrow           = document.getElementById(arrow_div);
    arrow.style.display = 'none';
    text.style.width = '250px';
    
    //heading.style.width = '260px'
    //heading.style.paddingTop  = '50px'
    //margin-left: 25px; width: 260px; margin-top: 0px; padding-top: 50px;
  }
}

function check_event_origin(event, origin_id)
{
  try {
    if (!event) var event = window.event;
    var target = (window.event) ? event.srcElement : event.target;
    var rel_target = (event.relatedTarget) ? event.relatedTarget : event.toElement;
    while (rel_target.id != origin_id && rel_target.nodeName != 'BODY') {
     rel_target = rel_target.parentNode;
     //console.log('parent ' + rel_target.nodeName + "," + target.id);
    }
    if (rel_target.id == origin_id) return false;
    // Mouseout took place when mouse actually left layer
    return true;
   //document.body.removeChild(obj("SemanticAds_Tooltip"));
 } catch(e) {} 
  return false;
}


//HTML-Generating-Functions
function removeChildren(parent)
{
    while (parent.firstChild)
    {
        parent.removeChild(parent.firstChild);
    }
}

function createImage(src, alt, opt_className)
{
  var el = document.createElement("img");
  el.src = src;
  el.alt = alt;
  if (opt_className) 
  {
      el.className = opt_className; 
  }
  return el;
}

function createDiv(opt_text, opt_className)
{
    var el = document.createElement("div");
    if (opt_text)
    {
        el.innerHTML = opt_text;
    }
    if (opt_className) 
    {
        el.className = opt_className; 
    }
    return el;
}

function createP(opt_className, opt_text)
{
    var el = document.createElement("p");
    if (opt_text)
    {
        el.innerHTML = opt_text;
    }
    if (opt_className) 
    {
        el.className = opt_className; 
    }
    return el;
}

function createH1(opt_className, opt_text)
{
    var el = document.createElement("h1");
    if (opt_text)
    {
        el.innerHTML = opt_text;
    }
    if (opt_className) 
    {
        el.className = opt_className; 
    }
    return el;
}

function createLink(href, opt_text, opt_target, opt_className, opt_divwrap)
{
    var el = document.createElement("a");
    el.href = href;
    if (opt_text)
    {
        el.innerHTML = opt_text;
    }
    if (opt_className)
    {
        el.className = opt_className;
    }
    if (opt_target)
    {
        el.target = opt_target;
    }
    if (opt_divwrap)
    {
        var div = this.createDiv(null, opt_className);
        div.appendChild(el);
        el = div;
    }
    return el;
}
function createSpan(opt_text, opt_className)
{
    var el = document.createElement("span");
    if (opt_text)
    {
        el.innerHTML = opt_text;
    }
    if (opt_className)
    {
        el.className = opt_className;
    }
    return el;
}