function validate_form() 
{

if (document.formular.personen.value=="")
{ alert ("Personen required");
  document.formular.personen.focus();
  return false; }

if (document.formular.vorname.value=="")
{ alert ("Vorname required");
  document.formular.vorname.focus();
  return false; }
 
if (document.formular.nachname.value=="")
{ alert ("Nachname required");
  document.formular.nachname.focus();
  return false; }

if (document.formular.adresse.value=="")
{ alert ("Adresse required");
  document.formular.adresse.focus();
  return false; }
  
if (document.formular.ort.value=="")
{ alert ("Ort required");
  document.formular.ort.focus();
  return false; }

if (document.formular.land.value=="")
{ alert ("Land required");
  document.formular.land.focus();
  return false; }		

if (document.formular.email.value.indexOf('@')==-1)		//E-Mail
{ alert ("E-Mail incorrect");
  document.formular.email.focus();
  return false; }

}