TIWAdvMessageDialog Modal Show

I would like to know if TIWAdvMessageDialog can display a modal message like WebApplication.ShowMessage and what i have to do for that.

TIWAdvMessageDialog emulates modal behavior by using an overlay (optionally semi transparent) over the page, so only the dialog is accessible and not the controls on the page from where the dialog is triggered. This overlay can be controlled with properties OverlayColor / OverlayOpacity