一个struts中关于标签的问题？谢谢各位给予解答！！

[PBsong]

下面是关于<tiles/>标签的内容：

<tiles:insert page="/Jsp/layout/mainLayout.jsp" flush="true">
<tiles:put name="header" value="/showHead.do" />
<tiles:put name="body" value="<%=bodyPath%>" />
<tiles:put name="right" value="/Jsp/common/list.jsp" />
</tiles:insert>

上面的前四行分别对应下面的两个错误：

"index.jsp": Error #: 302 : cannot access class org.apache.struts.taglib.tiles.InsertTag; java.io.IOException: class not found: class org.apache.struts.taglib.tiles.InsertTag at line 17
"index.jsp": Error #: 302 : cannot access class org.apache.struts.taglib.tiles.InsertTag; java.io.IOException: class not found: class org.apache.struts.taglib.tiles.InsertTag at line 17
"index.jsp": Error #: 302 : cannot access class org.apache.struts.taglib.tiles.PutTag; java.io.IOException: class not found: class org.apache.struts.taglib.tiles.PutTag at line 18
"index.jsp": Error #: 302 : cannot access class org.apache.struts.taglib.tiles.PutTag; java.io.IOException: class not found: class org.apache.struts.taglib.tiles.PutTag at line 18
"index.jsp": Error #: 302 : cannot access class org.apache.struts.taglib.tiles.PutTag; java.io.IOException: class not found: class org.apache.struts.taglib.tiles.PutTag at line 19
"index.jsp": Error #: 302 : cannot access class org.apache.struts.taglib.tiles.PutTag; java.io.IOException: class not found: class org.apache.struts.taglib.tiles.PutTag at line 19
"index.jsp": Error #: 302 : cannot access class org.apache.struts.taglib.tiles.PutTag; java.io.IOException: class not found: class org.apache.struts.taglib.tiles.PutTag at line 20
"index.jsp": Error #: 302 : cannot access class org.apache.struts.taglib.tiles.PutTag; java.io.IOException: class not found: class org.apache.struts.taglib.tiles.PutTag at line 20

同样的，别的地方只要用到该标签，一定出现同样的错误！

[PBsong]

怎么了，没有人气啊？
我自己顶一下！！