private void frmAddInventoryTransItem3_Load(object sender, EventArgs e)
 {
     txtQty.Text = 1.ToString();
     txtWeight.Text = 0.ToString("N3");
     this.ActiveControl = txtPLU;
     
     sc = SerialConnection.OpenConnection();
     sc.WeightReceived += new SerialDataReceivedEventHandler(WeightReceived);
 }