show the custom message in Django form
<p>Sorry, I'm not good at English. I have some problem for studying Django.
I wrote the below code to make a form. And I need to show the custom message when user didn't enter the value in text box.</p>

<pre><code>class ArticleForm(ModelForm):
    title = forms.CharField( error_messages={'required': 'Please enter title'}, 
                         max_length=128 , 
                         required=True,
                         widget=forms.TextInput(attrs={'size':60}))
    contents  = forms.CharField( required=True,
                         widget=forms.Textarea(attrs={'cols': 160, 'rows': 20}))
    email = forms.CharField(max_length=128, widget=forms.TextInput(attrs={'size':60}))
    writed_by = forms.CharField(max_length=100, 
                            required=True,
                            widget=forms.TextInput(attrs={'size':60}))
    class Meta:
        model  = Article
        fields = ["title", "writed_by", "email", "contents"]
</code></pre>

<p>I want to show 'Please enter title' message when didn't enter the title. But form shows the default message.</p>

<p>what is the problem in this code?</p>

<p>Thanks.</p>