function popup(theURL,winName,features) { //v2.0
  window.open(theURL,winName,features);
}

function popup_kontakt() { //v2.0
  window.open('kontakt.php','Kontakt','width=430,height=600');
}

function popup_impressum() { //v2.0
  window.open('impressum.html','Impressum','width=260,height=480');
}

function popup_contact() { //v2.0
  window.open('contact.php','Contact','width=430,height=600');
}

function popup_imprint() { //v2.0
  window.open('imprint.html','Imprint','width=260,height=480');
}