Posting a form in go and returning errors and the form content

post.go

type Data struct {
  PostData url.Values
	Errors    string
}

func Handler(w http.ResponseWriter, r *http.Request) {
	data := new(Data)
	if r.Method == "POST" {
		err := r.ParseForm()
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
		}
		cidade := &model.Cidade{}
    //I'm using the gorilla toolkit to decode the form
		err = decoder.Decode(cidade, r.Form)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
		}
    //This will validate the data
		err = self.Store.Save(cidade)
		if err != nil {
      //Here I just try to replace the line breaks to html, but the template engine sanitizes it :(
			data.Erros = strings.Replace(err.Error(), "\n", "<br/>", -1)
      //Here I get what was posted in the form the send it back
			data.PostData = r.Form
		} else {
      //just a redirect for testing
			http.Redirect(w, r, fmt.Sprintf("/cidade/?Id=", cidade.Id), http.StatusFound)
		}
	}
  err := tmpl.Execute(w, data)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}

//And in my template I have something like this:
<h1>Cidade</h1>
{{.Erros}}
<form action="" method="POST">
    <input type="text" name="Nome" Value="{{.PostData.Nome}}">
    <input type="text" name="UF">
    <input type="Submit">
</form>