function win(URL,NAME,W,H) {
        newWin = window.open(URL,NAME,"resizable=no,scrollbars=no,width=" + W + ",height=" + H);
        newWin.focus(); }
function win2(URL,NAME,W,H) {
        newWin = window.open(URL,NAME,"resizable=no,scrollbars=yes,width=" + W + ",height=" + H);
        newWin.focus(); }

function validate_form() {
  validity = true; // assume valid
  if (!check_email(document.form.EMail.value))
        { validity = false; alert('E-Mail address not valid!'); }
  else { win('letter/?'+document.forms[0].elements[0].value,'letter','250','150'); }
  return validity;
}

function check_empty(text) {
  return (text.length > 0);
}

function check_email(address) {
  if ((address == "")
    || (address.indexOf ('@') == -1)
    || (address.indexOf ('.') == -1))
      return false;
  return true;
}