alert message قبل Response.Redirect

وجدت الحل و اضعه للافادة لنا جميعا :

Dim message As String = "Upadate Successfull !!"
        Dim url As String = "/your page.aspx"
        Dim script As String = "{ alert('"
        script += message
        script += "');"
        script += "window.location = '"
        script += url
        script += "'; }"
        ScriptManager.RegisterStartupScript(Me.Page, Page.[GetType](), "alert", script, True)