How to use DropDownList in GridView

protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            GridData();
        }
    }
    void GridData()
    {
        sqlcmd = new SqlCommand("select *,CASE empstatus when 'Y' then 'Yes' else 'No' END as STATUS from emp", sqlcon);
        sqlcon.Open();
        da = new SqlDataAdapter(sqlcmd);
        dt.Clear();
        da.Fill(dt);
        if (dt.Rows.Count > 0)
        {
            GridView1.DataSource = dt;
            GridView1.DataBind();
        }   
    }
}

protected void GridView1_RowUpdating(object sender,GridViewUpdateEventArgs e)
    {

        GridViewRow row = GridView1.Rows[e.RowIndex];
        string eno;

        eno = GridView1.DataKeys[e.RowIndex].Value.ToString();

        TextBox empname = (TextBox)row.FindControl("txtempname");
        DropDownList status = (DropDownList)row.FindControl("DropDownList1");
        string selval;

        if (status.SelectedValue == "Yes")
        {
            selval = "Y";
        }
        else
        {
            selval = "N";
        }

        sqlcon.Open();
        sqlcmd = new SqlCommand("update emp set empname='" + empname.Text + "',empstatus='" + selval + "' where eno='" + eno + "'",sqlcon);
        sqlcmd.CommandType = CommandType.Text;
        sqlcmd.ExecuteNonQuery();
        sqlcon.Close();
        GridView1.EditIndex = -1;
        GridData();
    }