function checkEmail(){
    re = new RegExp("^[_a-zA-Z0-9\.\-]+@[_a-zA-Z0-9\.\-]+\.[a-zA-Z]{2,4}$");
    if (!re.test(document.getElementById("email").value)) {
      window.alert("Emailová adresa nemá správný formát");
      return false;
    } else {
    return true;
    }
}

function MM_openBrWindow(theURL,winName,features) {
  window.open(theURL,winName,features);
}