protected void btn_update_Click(object sender, EventArgs e)
 {
     using (AlmacenEntities modelo = new AlmacenEntities())
     {
         string nt  = nit.Value;
         string nam = name.Value;
         string add = address.Value;
         string ph  = phone.Value;
         modelo.PR_ClienteUpdate_Web(nt, nam, add, ph);
     }
     Response.Redirect("WebCliente.aspx");
 }