function getWindowSize() {
  // Browserbreite holen
  if (typeof(window.innerWidth) == 'number')
  {
    //Firefox and Netscape compliant
    width  = window.innerWidth;
    height = window.innerHeight;
    browser = "Mozilla";
    puffer = 60;
  }
  else if (document.documentElement && (document.documentElement.clientWidth || document.documentElement.clientHeight))
  {
    //IE 6+ in 'standards compliant mode'
    width  = document.documentElement.clientWidth;
    height = document.documentElement.clientHeight;
    browser = "IE6+";
    puffer = 0;
  }
  else if (document.body && (document.body.clientWidth || document.body.clientHeight))
  {
    //IE 4 compatible
    width  = document.body.clientWidth;
    height = document.body.clientHeight;
    browser = "IE4";
    puffer = 0;
  }

  height = (height - puffer);

  return {'width': width, 'height': height};
}

function hoehe() {
  var bg = document.getElementById("bg_meldung");
  var box = document.getElementById("meldung");

  var masse = getWindowSize();
  var mitte = Math.round(masse["width"] / 2) - 125;

  // bg.style.height = masse["height"] + "px";
  box.style.left = mitte + "px";
}