TChromium and onBeforePopup - Delphi how to prevent new windows from being created?

Question

Delphi

good day
i block new windows
procedure MainThread.mainchromeBeforePopup(Sender: TObject;
const browser: ICefBrowser; const frame: ICefFrame; const targetUrl,
targetFrameName: ustring; targetDisposition: TCefWindowOpenDisposition;
userGesture: Boolean; var popupFeatures: TCefPopupFeatures;
var windowInfo: TCefWindowInfo ; var client: ICefClient;
var settings: TCefBrowserSettings; var noJavascriptAccess: Boolean;
out Result: Boolean);
start
Result:=True;
end;
but message windows are also blocked. How can this be avoided