/*
 *  Überprüft die Email
 */
function checkEmailStr(s)
{
  var a = false;
  var res = false;
  if(typeof(RegExp) == 'function')
  {
   var b = new RegExp('abc');
   if(b.test('abc') == true)
     a = true;
  }

  if(a == true)
  {
   reg = new RegExp('^([a-zA-Z0-9\\-\\.\\_]+)'+'(\\@)([a-zA-Z0-9\\-\\.]+)'+'(\\.)([a-zA-Z]{2,4})$');
   res = (reg.test(s));
  }
  else
   res = (s.search('@') >= 1 && s.lastIndexOf('.') > s.search('@') && s.lastIndexOf('.') >= s.length-5)

  return(res);
}


/*
 *  Überprüft das Kontakt Formular
 */
function check_Contact()
{
  var name = window.document.getElementsByName('name_field')[0];
  if(name == null)
  {
     window.alert("JavaScript Fehler check_Contact");
     return false;
  }
  var cname = window.document.getElementById('c_name');
  if(cname == null)
  {
     window.alert("JavaScript Fehler check_Contact");
     return false;
  }
  var email_field = window.document.getElementsByName('email_field')[0];
  if(email_field == null)
  {
     window.alert("JavaScript Fehler check_Contact");
     return false;
  }
  var cemail = window.document.getElementById('c_email');
  if(cemail == null)
  {
     window.alert("JavaScript Fehler check_Contact");
     return false;
  }
  var message = window.document.getElementsByName('message_field')[0];
  if(message == null)
  {
     window.alert("JavaScript Fehler check_Contact");
     return false;
  }
  var cmessage = window.document.getElementById('c_message');
  if(cmessage == null)
  {
     window.alert("JavaScript Fehler check_Contact");
     return false;
  }

  if (name.value == "")
    cname.innerHTML = 'Bitte geben Sie einen Namen an.';
  else
    cname.innerHTML = '';

  if (message.value == "")
    cmessage.innerHTML = 'Bitte geben Sie eine Nachricht an.';
  else
    cmessage.innerHTML = '';

  if (email_field.value == "")
    cemail.innerHTML = 'Bitte geben Sie eine E-Mail an.';
  else
    cemail.innerHTML = '';

  var email_checker = true;
  if (email_field.value != "")
    email_checker = checkEmailStr(email_field.value);

  if (email_checker == false)
  {
    cemail.innerHTML = 'Bitte überprüfen Sie die E-Mail.';
    return false;
  }

  if (message.value == "" || name.value == "" || email_field.value == "")
    return false;
  else
    return true;
}