function Validar(form)
{
  if (form.nombre.value == "")
  {
  alert("Please, enter your name"); form.nombre.focus(); 
  document.getElementById("nombre").style.backgroundColor = "#FF5357";
  return;
  } else{ 
    document.getElementById("nombre").style.backgroundColor = "#ffffff";
	}
//-----------------------------------------------------------------------------------------------
//-----------------------------------------------------------------------------------------------
 
  if (form.email.value == "")
  {
  alert("Please, enter your e-mail"); form.email.focus(); 
  document.getElementById("email").style.backgroundColor = "#FF5357";
  return;
  } else{ 
    document.getElementById("email").style.backgroundColor = "#ffffff";
	}
if (form.email.value.indexOf('@', 0) == -1 ||
      form.email.value.indexOf('.', 0) == -1)
  { alert("Please, enter your e-mail correctly"); form.email.focus(); return; }

//-----------------------------------------------------------------------------------------------
  if (form.comentario.value == "")
  {
  alert("Don't forget your comment!"); form.comentario.focus(); 
  document.getElementById("comentario").style.backgroundColor = "#FF5357";
  return;
  } else{ 
    document.getElementById("comentario").style.backgroundColor = "#ffffff";
	}

 
  form.submit();
}