protected void btnDelete_Click(object sender, EventArgs e)
 {
     if (Session["CustomerPKID"].ToString() != "" && long.TryParse(Session["CustomerPKID"].ToString(), out _PKID))
     {
         _PKID = long.Parse(Session["CustomerPKID"].ToString());
         _customer = new CustomerClass(_PKID);
         _customer.deleteRecord(_PKID);
         Session["CustomerPKID"] = "";
     }
     fillGridView();
 }
 protected void Page_Load(object sender, EventArgs e)
 {
     if (Session["CustomerPKID"].ToString() != "" && long.TryParse(Session["CustomerPKID"].ToString(), out _PKID))
     {
         _PKID = long.Parse(Session["CustomerPKID"].ToString());
         _customer = new CustomerClass(_PKID);
         if (!Page.IsPostBack)
         {
             displayRecord();
         }
     }
     else
     {
         _customer = new CustomerClass();
     }
     populateEmployeeComboBox();
 }