private void frmIventoryReport_Load(object sender, EventArgs e) { DataTable dt1 = bllss4.getAllWareHouses(); comboBox1.DataSource = dt1; comboBox1.DisplayMember = "WareHouseName"; comboBox1.ValueMember = "ID"; dt2 = bllss4.getIventoryReport(int.Parse(comboBox1.SelectedValue.ToString())); dataGridView1.DataSource = dt2; }