How to retrieve the values from a database and display it in proper HTML format

SqlParameter Screenname = new SqlParameter("@ScreenName", GlobalList[count]);
                Screenname.SqlDbType = SqlDbType.VarChar;
                SqlCommand cmd_sel = new SqlCommand("Select * from userInfo where ScreenName=@ScreenName ", con);
                cmd_sel.Parameters.Add(Screenname);
                con.Open();
                SqlDataReader dr = cmd_sel.ExecuteReader();
                if (dr.Read())
                {
                                        str.AppendFormat("<ul> <div>  <div> <div>  ");
                    str.AppendFormat("<li> <input type=\"button\" id=\"btnTextChat\" value=\"TextChat\" /> </li>");
                    str.AppendFormat("<li><input type=\"button\" id=\"btnSendMessage\" value=\"Send Message\" />  </li> ");
                    str.AppendFormat("<li><input type=\"button\" id=\"btnAudioVideoChat\"  value=\"Audio-Video Chat\" /> </li>");
                    str.AppendFormat("<li><input type=\"button\" id=\"btnWink\" value=\"Wink\" /> </li>");
                    str.AppendFormat("</ul> </div>  </div> </div>  ");
                    count++;
                }
                con.Close();