Getting a selected value from the drop down list inside a GridView on Update

[Norris Chappell]

I have a DataGridView, each row has Edit button. After it's clicked, SAPLeader column turns into a drop down list where users can select value. Edit button becomes Update - Getting a null! For some reason the SAPLeader field is not showing my update.The issue is when I display my datagridview gvAccountStaff, I have a column called SAPLeader which has a dropdownlist. When I select a name in the list it errors: Object reference not set to an instance of an object. The SAPLeader field is null. I tried replacing the @SAPLeader with the ddl1.SelectedValue that didn't worked neither. When I debug the event gvAccountStaff_RowDataBound, the datalist shows for the SAPLeader field. However, the dropdownlist is not udpdating when I fire event gvAccountStaff_RowUpdating the value is null by the time it gets there. The rest of the fields are fine. Do I need to bind the gridview again with the datalist? I not sure why it doesn't work. Thanking anyone in advance, Norris aspx code: <%-- --%> <%----%>

protected void Page_Load(object sender, EventArgs e)
{
lblMsg.Text = "";
if (!Page.IsPostBack)
{

            gvAccountStaff.DataBind();
            BindSubjectData();
        }
    }
    call to bind gridview
    public class DropDownData
    {
        public DropDownData(int id, string displaytext)
        {
            iD = id;