c# 办公软件有一个DropDownList灰显

Question

<td bgcolor="#efefef" class="cpx12hei" height="24" width="35%">
                                                    <%--<asp:TextBox ID="txtsalesman" runat="server" Width="90%" Height="20px"></asp:TextBox>--%>
                                                    <asp:DropDownList ID="dropSalesman" Width="100" runat="server"  >
                                                    </asp:DropDownList>
                                                </td>                string salesMan = NewReader["salesMan"].ToString().Trim();
                string sql_Employee = "select id from Employee where Name='"+salesMan+"'";
                SqlDataReader NewReaderE = List.GetList(sql_Employee);
                if (NewReaderE.Read())
                { dropSalesman.Text = NewReaderE["id"].ToString(); }