jsp，servlet遇到的问题

java错误信息
java.lang.ClassCastException: org.apache.catalina.core.DefaultInstanceManager cannot be cast to org
修改了tomcat里的context.xml文件，
在context 元素下添加
如下面所示：
<Context>
    <!-- Default set of monitored resources -->
    <WatchedResource>WEB-INF/web.xml</WatchedResource>
    <!-- Uncomment this to disable session persistence across Tomcat restarts -->
  
安装java需要配置的路径

export JAVA_HOME=/opt/jdk1.6.0_45
export CLASSPATH=$JAVA_HOME/jre/lib/rt.jar:.
export PATH=/opt/jdk1.6.0_45/bin:$PATH

 
java错误信息
 java.lang.ClassCastException: org.apache.catalina.core.DefaultInstanceManager cannot be cast to org
修改了tomcat里的context.xml文件，
在context 元素下添加 <!--
    <Manager pathname="" />
    -->
    <!-- Uncomment this to enable Comet connection tacking (provides events
         on session expiration as well as webapp lifecycle) -->
    <!--
    <Valve className="org.apache.catalina.valves.CometConnectionManagerValve" />
    -->
    [b]<Loader delegate="true" />[/b]
</Context>

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onclick跳转
①onclick="javascript:window.location.href='URL'"
　　②onclick="location='URL'"
　　③onclick="window.location.href='URL?id=11'"
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button使用文本框中的内容
<input type="text" name="my" id="my"/>
<button
onclick="location.href='c.jsp?sname='+document.getElementById('my').value">Thev query</button>
String sql="select * from users where name like '"+myname+"%'";
out.println("<button onclick="+"location.href='add.jsp'>add</button>");
out.println("<button onclick="+"location.href='add.jsp?newname="+sqlmname+"'>add</button>");