private void Button4_Click(object sender, EventArgs e) { Hide(); var frm = new frmSalesRecord1(); frm.DataGridView1.DataSource = null; frm.dtpInvoiceDateFrom.Text = DateTime.Today.ToString(); frm.dtpInvoiceDateTo.Text = DateTime.Today.ToString(); frm.GroupBox3.Visible = false; frm.DataGridView3.DataSource = null; frm.cmbCustomerName.Text = string.Empty; frm.GroupBox4.Visible = false; frm.DateTimePicker1.Text = DateTime.Today.ToString(); frm.DateTimePicker2.Text = DateTime.Today.ToString(); frm.DataGridView2.DataSource = null; frm.GroupBox10.Visible = false; frm.FillCombo(); frm.label9.Text = label6.Text; frm.Show(); }