超链接无法访问servlet的问题（错误代码404）
超链接访问servlet <h3><A href="/UsercheckServlet?tager="+admin>管理员入口</A></h3>
可是当我点击超链接时，却找不到servlet（错误代码404）


web.xml配置如下：
<servlet>
  <servlet-name>dis</servlet-name>
  <servlet-class>com.wl.control.UsercheckServlet</servlet-class>
  </servlet>
  <servlet-mapping>
  <servlet-name>dis</servlet-name>
  <url-pattern>/UsercheckServlet</url-pattern>
  </servlet-mapping>
我的网站目录是这样的 F:\Program Files\Apache Software Foundation\Tomcat 7.0\webapps\stuCor (stuCor是我的网站)

以下是servlet（很简单的，就几行代码，麻烦各位高手看完）

package com.wl.control;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class UsercheckServlet extends HttpServlet {

 /**
 * The doGet method of the servlet. <br>
 *
 * This method is called when a form has its tag value method equals to get.
 *  
* @param request the request send by the client to the server
 * @param response the response send by the server to the client
 * @throws ServletException if an error occurred
 * @throws IOException if an error occurred
 */
 public void doGet(HttpServletRequest request, HttpServletResponse response)
 throws ServletException, IOException {

 String u=request.getParameter("tager");
 try {if (u.equals("a")){
 request.getRequestDispatcher("1.jsp").forward(request, response);
 }
 else if (u.equals("b")){
 request.getRequestDispatcher("2.jsp").forward(request, response);
 }
 }catch (Exception ex){
 ex.printStackTrace();
 }


 }

 /**
 * The doPost method of the servlet. <br>
 *
 * This method is called when a form has its tag value method equals to post.
 *  
* @param request the request send by the client to the server
 * @param response the response send by the server to the client
 * @throws ServletException if an error occurred
 * @throws IOException if an error occurred
 */
 public void doPost(HttpServletRequest request, HttpServletResponse response)
 throws ServletException, IOException {
 this.doGet(request, response);



 }

}
请各位高手指点 我哪出错了 谢谢啦

------解决方案--------------------
<h3><A href="<%=request.getContextPath()%>/UsercheckServlet?tager="+admin>管理员入口</A></h3>试试
不好用的话，把Tomcat换个路径之间的没有空格的地方