function validate(form, which)
{
 if(which=="dotazy")
 {
  if(form.text.value=="")
   {
    alert('Vyplòte text dotazu.');
    form.text.focus();
    return false;
   }
  }
 if(which=="mail")
  {
   if(form.text.value=="")
   {
    alert('Zadejte text e-mailu!');
    form.text.focus();
    return false;
   }
 }
}