protected void OnTreeviewServicesCursorChanged(object sender, EventArgs e)
{
TreeIter iter;
bool isSelect = treeviewServices.Selection.CountSelectedRows() == 1;
bool MeterOk = false;
if (isSelect && treeviewServices.Selection.GetSelected (out iter))
MeterOk = servicesWithMeters.Contains((int)ServiceListStore.GetValue(iter, (int)ServiceCol.service_id));
buttonDelService.Sensitive = isSelect;
buttonFromMeter.Sensitive = MeterOk;
}