Hi, I would like to know how I can leave the screen that launches the unused popup with the background as dark as I show in the screenshot below, I'm programming asp.net with visual basic

I want to open my page incidencias.aspx as if it were a popup, can I do that?

Dim newWin As String = "window.open('Incidencias.aspx', '_blank', 'location=true', 'status=true', 'scrollbars=true,'width=700,height=500,')"
ClientScript.RegisterStartupScript(Me.GetType(), "popup", newWin, True)