form认证

<authentication mode="Forms">
      <forms name=".ChinaMobileSMSFormsAuth" loginUrl="login.aspx" defaultUrl="chinamobilesms/default.htm" protection="All" timeout="120" />
    </authentication>
    <authorization>
      <deny users="?"/>
      <!-- 允许所有用户 -->
      <!--  <allow     users="[逗号分隔的用户列表]"
                             roles="[逗号分隔的角色列表]"/>
                  <deny      users="[逗号分隔的用户列表]"
                             roles="[逗号分隔的角色列表]"/>
            -->
    </authorization>

<!--排除个别不要认证的页面-->

  <location path="CheckCodeImage.aspx">
    <system.web>
      <authorization>
        <allow users="*"/>
      </authorization>
    </system.web>
  </location>