j2ee的问题，求大神指导。。

还有整个项目的跟目录下也有红叉叉
（报错。这里有个红色XX）<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
//红XX提示这句话错误。。xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/j2ee/web-app_2_5.xsd">
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
<resource-ref>
      <description>DB Connection</description>
       <res-ref-name>web</res-ref-name>
      <res-type>javax.sql.DataSource</res-type>
      <res-auth>Container</res-auth>
</resource-ref>
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>servlet_Insert</servlet-name>
    <servlet-class>servlet_Insert</servlet-class>
  </servlet>
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>servlet_delete</servlet-name>
    <servlet-class>servlet.servlet_delete</servlet-class>
  </servlet>
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>servlet_update</servlet-name>
    <servlet-class>servlet.servlet_update</servlet-class>
  </servlet>  <servlet-mapping>
    <servlet-name>servlet_Insert</servlet-name>
    <url-pattern>/servlet/servlet_Insert</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>servlet_delete</servlet-name>
    <url-pattern>/servlet/servlet_delete</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>servlet_update</servlet-name>
    <url-pattern>/servlet/servlet_update</url-pattern>
  </servlet-mapping></web-app>