// window.madvertise_ad_params = {
//   site:'token',
//   format:'html'
// }
(function() {
  // what do we need
  conf = window.madvertise_ad_params;
  to_param_string = function(hash) {
    var result = [];
    for(var k in hash) {
      result.push(k+"="+encodeURIComponent(hash[k]));
    }
    return result.join('&');
  };
  
  // override html for now, as several old browsers do not like it
  if(window.madvertise_ad_params.format == 'html')
    window.madvertise_ad_params.format = 'html-js';
  
  
  now = (new Date).getTime();
  var base_url = (conf.base || "http://ad.madvertise.de/site/") + conf.site + "?";
  var params = {
    format   : window.madvertise_ad_params.format || 'html-js',
    requester: 'js',
    version  : 'js-3',
    ref      : document.referrer,
    ua       : navigator.userAgent,
    token    : "JST-" + Math.floor(Math.random()*10000000).toString(36),
    timezone : -(new Date).getTimezoneOffset(),
    timestamp: now,   
  }                                              
  if(window.madvertise_ad_params.click_url_template)
    params['click_url_template'] = window.madvertise_ad_params.click_url_template;
  
  var src = base_url + to_param_string(params);
  
  var w = 320;  
  if(screen.availWidth < w)
    w = screen.availWidth;
  
  var h = 53;
  if(screen.availHeight < h)
    h = screen.availHeight;
  
  var ad_tag = null;
  
  if(params.format == 'html-js') {
    ad_tag = "<script type='text/javascript' src=" + src + '"></script>';
  } else {
    ad_tag = '<div><iframe name="madvertise_ad" src="' + src + '" marginwidth="0" marginheight="0" vspace="0" hspace="0" allowtransparency="true" scrolling="no" frameborder="0" width="' + w + '" height="' + h + '"></iframe></div>';
  }
  document.write(ad_tag);
})();