How to give focus to FormItem

Do not tell me how to give focus to FormItem in DynamicForm ?
The following code does not give the expected result:

"initWidget": function() {
var that = this;
this.Super("initWidget", arguments);;
this.loginForm = isc.DynamicForm.create({
"autoDraw": false,
"fields": [..., {
"colSpan": 2,
"canFocus": true,
"selectOnFocus": true,
"name": "loginButton",
"click": function(form, item) {
that.doLogin(form, item);
},
"align": "center",
"title": "\u0412\u043E\u0439\u0442\u0438 ...",
"width": 100,
"editorType": "ButtonItem"
}]
});
this.loginForm.focusInItem("loginButton");
this.addItem(this.loginForm);
}

Thanks