function chkFormular () {
  if (document.Formular.kont_name.value == "") {
    alert("Please enter your name!");
    document.Formular.kont_name.focus();
    return false;
  }
  if (document.Formular.kont_mail.value == "") {
    alert("Please enter your e-mail-address!");
    document.Formular.kont_mail.focus();
    return false;
  }
  if (document.Formular.kont_mail.value.indexOf("@") == -1) {
    alert("This isn't an e-mail-address!");
    document.Formular.kont_mail.focus();
    return false;
  }
  if (document.Formular.kont_summe.value == "") {
    alert("Please enter amount!");
    document.Formular.kont_summe.focus();
    return false;
  }
  /*
  if (document.Formular.kont_nachricht.value == "") {
    alert("Bitte geben Sie eine Nachricht ein!");
    document.Formular.kont_nachricht.focus();
    return false;
  }
  */
}