#webcontrol obj.executejavascript

You can use LoadHtml method, but only after document is fully loaded (dont confuse with DocumentReadyState.Ready) It works for me at least: private void WebControl_DocumentReady(object sender, DocumentReadyEventArgs e) { if (e.ReadyState != DocumentReadyState.Loaded) return; }

But as an initialisation, you should use Source property, like you wrote in your third update