asp.net 文件上传出错：Maximum request length exceeded 解决方法

<configuration>
    <system.web>       
        <httpRuntime maxRequestLength="102400" useFullyQualifiedRedirectUrl="true" minFreeThreads="8" minLocalRequestFreeThreads="4" appRequestQueueLimit="100" enableVersionHeader="true"/>
    </system.web>
</configuration>