function HideIt() {
        document.getElementById('name').innerHTML='';
        document.getElementById('email').innerHTML='';
        document.getElementById('message').innerHTML='';
}

   
function check() {
     document.getElementById('form_name').innerHTML='';
     document.getElementById('form_email').innerHTML='';
     document.getElementById('form_message').innerHTML='';
     if(self.document.forms.f.name.value == "") {
        document.getElementById('form_name').innerHTML='Zadajte Vaše meno!';
        return false;
     }
   
     if(self.document.forms.f.email.value == "") {
        document.getElementById('form_email').innerHTML='Neplatný email!';
        return false;
     }
     if(self.document.forms.f.message.value == "") {
        document.getElementById('form_message').innerHTML='Vložte správu!';
        return false;
     }
   return true;
  }