//global variable for error flag
var errfound = false;
//function to validate by length
function ValidLength(item, len) {
   return (item.length >= len);
}
//function to validate an email address
function ValidEmail(item) {
   if (!ValidLength(item, 5)) return false;
   if (item.indexOf ('@', 0) == -1) return false;
   return true;
}
// display an error alert
function error(elem, text) {
// abort if we already found an error
   if (errfound) return;
   window.alert(text);
   elem.select();
   elem.focus();
   errfound = true;
}
// main validation function
function Validate() {
   errfound = false;
   if (!ValidLength(document.regform.Name.value,3))
      error(document.regform.Name,"Lautet Ihr Name wirklich so ?");
   
   if (!ValidLength(document.regform.Vorname.value,3))
      error(document.regform.Vorname,"Ist das Ihr Vorname ?");
   
   if (!ValidLength(document.regform.Strasse.value,5))
      error(document.regform.Strasse,"keine gültige Straßenbezeichnung");
	  
   if (!ValidLength(document.regform.plz.value,5))
      error(document.regform.ort, "In Deutschland sind die PLZ 5-stellig!");	  
	  
   if (!ValidLength(document.regform.ort.value,4))
      error(document.regform.ort, "Wo wohnen Sie ?");
          
  return !errfound; /* true if there are no errors */
}