//根据密码长度显示安全条                        <ul class="clear">                      <li>密　　码：</li>                      <li> <input type="password" id="pwd" name="pwd" class="in" onKeyUp=pwStrength(this.value) onBlur=pw_y("pwd","pwd1")></li>                      <li><em class="red">*</em></li>                      <li class="i2 grey"><table border="0" bordercolor="#cccccc" style='display:marker'>                      <tr align="center">                          <td  id="strength_L"  bgcolor="#eeeeee">弱</td>                          <td  id="strength_M" bgcolor="#eeeeee">中</td>                          <td id="strength_H" bgcolor="#eeeeee">强</td>                      <td align="left" >                        <label id="pwd1">使用数字，字母，下划线，长度在 6 - 20 个字符之间</label></td>                          </tr>                      </table>                                       </li>                      </ul>    function pwStrength(pwd){      O_color="#eeeeee";      L_color="#FF0000";      M_color="#FF9900";      H_color="#33CC00";      if (pwd==null||pwd==''){          Lcolor=Mcolor=Hcolor=O_color;      }else{          S_level=checkStrong(pwd);          switch(S_level) {              case 0:                  Lcolor=Mcolor=Hcolor=O_color;              case 1:                  Lcolor=L_color;                  Mcolor=Hcolor=O_color;                  break;              case 2:                  Lcolor=Mcolor=M_color;                  Hcolor=O_color;                  break;              default:                  Lcolor=Mcolor=Hcolor=H_color;              }      }      document.getElementById("strength_L").style.background=Lcolor;      document.getElementById("strength_M").style.background=Mcolor;      document.getElementById("strength_H").style.background=Hcolor;      return;  }