hi to all.

i'm trying to use odoo 10. I created a new field (x_number) in contact details (website portal) but when i click on submit button, i get this error : Unknown field 'x_number'
NB: i have already create this field in the database via the interface. and in the website_portal_templates.xml file, i added this :

<div t-attf-class="form-group #{error.get('x_number') and 'has-error' or ''} col-lg-6">
                                        <label class="control-label" for="x_number">Number</label>
                                        <input type="tel" name="x_number" class="form-control" t-att-value="x_number" />
  </div>
I'm a newer on Odoo ERP.
please help me to fix this.