How toshow name and insert values (name's ID ) from combobox

Question

c# Windows Forms.

 

 

 

public void Load()

{

DataRow dr;

con.Open();

SqlCommand cmd = new SqlCommand("select * from city", con);

SqlDataAdapter sda = new SqlDataAdapter(cmd);

DataTable dt = new DataTable();

sda.Fill(dt);

dr = dt.NewRow();

dr.ItemArray = new object[] { 0, "--Select City--" };

dt.Rows.InsertAt(dr, 0);

comboBoxunit.ValueMember = "city_ID";

comboBoxunit.DisplayMember = "city";

comboBoxunit.DataSource = dt;

con.Close();

}