dopostメソッドが実行されない理由が分かりません・・・・。

プログラミング初心者です
dopostメソッドが実行されない理由が分かりません・・・・。
デバックで試すと送信ボタンを押下直後に404のエラーが表示されてしまいます

<%@page import="controller.OkidoInstitute"%>
<%@page import="java.util.Arrays"%>
<%@page import="java.util.List"%>
<%@ page contentType="text/html; charset=Windows-31J"%>

<%
@SuppressWarnings("unchecked")
	List<PokeBean> list = (List<PokeBean>) request.getAttribute("list");
%>

<html>
<head>
<title>選択</title>
</head>
<body>
	<div align="center">
		<img src="./img/A.jpg">
	</div>
	<br>
		<b>選択してください</b>
	<br>
	<form action="id" method="post">
		<select>
			<%
				for (int i = 0; i < list.size(); i++) {
					PokeBean pull = list.get(i);
			%>
					<option value="<%=pull.getId() %>"><%=pull.Name()%></option>
			<%
				}
			%>
		</select> <input type="submit" value="送信">
	</form>
</body>
</html>

～～上記はdoGetのため省略～～
	public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {

		Poke poke = new Poke();

		try {
			int id = Integer.parseInt(request.getParameter("id"));
			List<PokeBean> pokeid = poke.pokeInfo(monsterid);
			request.setAttribute("poke", pokeid);

			target = "/PictureBook.jsp";

		} catch (Exception e) {
			e.printStackTrace();

		} finally {
			ServletContext context = this.getServletContext();
			RequestDispatcher dispatcher = context.getRequestDispatcher(target);
			dispatcher.forward(request, response);
		}
	}
}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://xmlns.jcp.org/xml/ns/javaee"
	xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
	id="WebApp_ID" version="3.1">
 	<display-name>pokeWeb</display-name>

 	<!-- servlet・servlet-mapping -->

 	<welcome-file-list>
    	<welcome-file>pokeSelect</welcome-file>
  	</welcome-file-list>

  	<!-- servlet -->
	<servlet>
		<servlet-name>Poke</servlet-name>
		<servlet-class>controller.Institute</servlet-class>
	</servlet>

	<servlet-mapping>
		<servlet-name>Poke</servlet-name>
		<url-pattern>/pokeSelect</url-pattern>
	</servlet-mapping>


</web-app>