private void button1_Click(object sender, EventArgs e) { UserRentals userRentals; this.Visible = false; string selectedUser = comboBox1.SelectedItem.ToString(); string type = mrd.getUserType(selectedUser); if (type == "customer") { userRentals = new UserRentals(selectedUser); userRentals.Show(); } if (type == "seller") { SellerMenu sellerMenu = new SellerMenu(); sellerMenu.Show(); } }