When defining your fields in the form, add showNone: false
{ name: 'field', type: 'list', options: {
items: [{ id: 0, txt: 'Adams, John' }, { id: 1, text: 'Adams2, John' }],
showNone: false }
},
In a similar way you can remove - none - for regular fields. See http://w2ui.com/web/docs/form/fields for more information.