// JavaScript Document

function test_mail(string) {
   if (string.search(/^\w+((-\w+)|(\.\w+))*\@\w+((\.|-)\w+)*\.\w+$/) != -1)
      return true;
   else
      return false;
}

function mailReady(form) {
   if (test_mail(form.mail.value) == false) {
      alert("Zadejte prosím e-mail");
      form.mail.focus();
      return false;
   } 
}