void ibtnDelete_Click(object sender, ImageClickEventArgs e)
{
for (int i = 0; i < trvSupplier.CheckedNodes.Count; i++)
{
int SupplierID = Convert.ToInt32(trvSupplier.CheckedNodes[i].Value);
SupplierManager.DeleteLogical(SupplierID);
}
FillSupplierTree();
ExitMode();
upnlSupplierItem.Update();
}
#endregion