private void Form1_Load(object sender, EventArgs e) { PackageClassDataContext dbContext = new PackageClassDataContext(); this.cboProducts.SelectedValueChanged -= new System.EventHandler(this.CboProducts_SelectedValueChanged); // disable SelectedValueChanged event LoadComboBoxProd(); this.cboProducts.SelectedValueChanged += new System.EventHandler(this.CboProducts_SelectedValueChanged); // enable it again }