How to Enable a Dropdownlist

protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
      {
          try
          {
              if (Label5.Text.Trim() == Label13.Text.Trim())
              {
                  DropDownList2.Enabled = true;
              }
              SqlConnection dbconn = new SqlConnection(ConfigurationManager.ConnectionStrings["UsersConnectionString"].ConnectionString);
              dbconn.Open();
              //string sqltemp = "select from Status_Remarks where OutgoingRequestID ='" + Label10.Text + "' ";
              //SqlCommand com = new SqlCommand(sqltemp, dbconn);
              string sqltemp1 = "update Status_Remarks set Div_Officer_Remarks='" + DropDownList1.Text + "'where OutgoingRequestID ='" + Label10.Text + "'";
              com = new SqlCommand(sqltemp1, dbconn);
              com.ExecuteNonQuery();
              dbconn.Close();
          }