We are going to deploy the new yiiframework.com website on March 23, 2018 from 8:00 to 12:00 UTC.
Website and Yii documentation will not be available in this time frame. Check the news for more details.
I build this simple PHP class (DialogBox.php at the bottom of this wiki) to help you in the dialog box usage on Yii applications. The goal is run any Yii actions into this dialog box and return the resulting value to the calling instance.