```
permalinkWindowConfig.items = [
    permalinkTextField,
    warningLabel
];
if (this.shortnerCreateURL) {
    var shortButton = new Ext.Button({
        // ...
    });
    permalinkWindowConfig.buttons.push(shortButton);
    if (this.email) {
        this.emailField = new Ext.form.TextField({
            fieldLabel: this.emailText
        });
        permalinkWindowConfig.items.push(this.emailField);
    }
}
```