Help on storing combo or drop down values in the database.

How do I  ensure that values item databound  vales are being  stored in the database. Forexample if new  option1 is selected  "A" should be stored in  the database at the time of running insert or update  sql  database table.
The csharp  code I am using is as follows;
private void gCrop_ItemDataBound(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
        {
         //data binding to combo box
            DataGridItem dgi = e.Item;

            if ((dgi.ItemType == ListItemType.Item) || (dgi.ItemType == ListItemType.AlternatingItem))
            {
              &nbs ...