Listing 3: Adding Form1 class variables.

public class Form1 : System.Windows.Forms.Form
{
    private System.Windows.Forms.TrackBar trackBar1;
    private System.Windows.Forms.Label label1;
    private System.Windows.Forms.Label label2;
    private System.Windows.Forms.Label label3;
    /// <summary>
    /// Required designer variable.
    /// </summary>
    private int defaultRsrcMgrSess; // Default Resource Manager session
    private int funcGenSess;        // functionGenerator session
    private byte [] programMessage = new byte[256];
 ...
}