function showver() {
alert("optimized for firefox\n\nmin. resolution:1024x768\n\noptimal resolution:1280x1024");
}
function windowopen(addr,name,h,b) {
window.open(addr,name,'width='+b+',height='+h+',toolbar=no,location=no,status=yes,menubar=no,scrollbars=yes,resizable=yes');
}
function validate_newsletter() {
 validity = true; // assume valid
 if (!check_email(document.newsletter.email.value))
  { validity = false; alert('E-Mail Addresse ist ungültig!'); }
 return validity;
}
function check_empty(text) {
 return (text.length > 0); // gibt false zurück wenn leer
}
function popUp (url, width, height, name) {
   winFeatures = "width=" + width + ",height=" + height + ",menubar=no,resizable=no,scrollbars=yes,status=no,toolbar=no,location=no";
   spawn = window.open(url,name,winFeatures);
}
function check_empty(text) {
     return (text.length > 0); // gibt false zurück wenn leer
    }
function check_email(address) {
     if ((address == "") || (address.indexOf ('@') == -1) || (address.indexOf ('.') == -1)) {
      return false;
     } else {
      return true;
     }
    }
function check_url(address) {
     if ((address == "") || (address.indexOf ('http://') == -1) || (address.indexOf ('.') == -1)) {
      return false;
     } else {
      return true;
     }
    }