private void tsbInventoryIn_Click(object sender, EventArgs e)
{
InventoryIn inventory = new InventoryIn();
inventory.MdiParent = this;
inventory.Show();
}
private void tsbInventoryOut_Click(object sender, EventArgs e)
{
string direction = "out";
InventoryIn inventory1 = new InventoryIn(direction);
inventory1.MdiParent = this;
inventory1.Show();
}