Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim strMessaggio As String = "Variabile Passata"
        Dim strJS As String = "ShowMessage('" & strMessaggio & "');"
        ScriptManager.RegisterStartupScript(Page, Page.GetType(), Guid.NewGuid().ToString(), strJS, True)

    End Sub