function stylesheet(inhalt) {
  var breite = window.innerWidth;
  var inhalt;
  if (breite >= 1500){
    document.getElementById('style_width').href = "css/style1500.css";
    document.getElementById('style_inhalt').href = "css/style1500_" + inhalt + ".css";
  }
  if (breite >= 1900){
    document.getElementById('style_width').href = "css/style1900.css";
    document.getElementById('style_inhalt').href = "css/style1900_" + inhalt + ".css";
  }
}