新人请教有关dwr的问题

我刚开始学习dwr 配置好所以文件后 在测试dwr的时候
engine.js出现unterminated string literal的错误是怎么回事？
util.js报DWREngine.setPreHook is not a function 请各位帮我看一下
dwr配置文件：

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://getahead.ltd.uk/dwr/dwr20.dtd">
<dwr>
 <allow>
	<create creator="new" javascript="sysCmpService" scope="request">
		<param name="class" value="net.eow.core.util.StringUtil" />
	</create>
	</allow>
</dwr>

web.xml:

  
  <!-- dwr -->
	 <servlet>
		<servlet-name>dwr-invoker</servlet-name>
		<servlet-class>
			org.directwebremoting.servlet.DwrServlet
		</servlet-class>
		<init-param>
			<param-name>debug</param-name>
			<param-value>true</param-value>
		</init-param>
		<init-param>
			<param-name>config-files</param-name>
			<param-value>
				/WEB-INF/classes/dwr/dwr-sys.xml
			</param-value>
		</init-param>
		<init-param>
			<param-name>pollAndCometEnabled</param-name>
			<param-value>true</param-value>
		</init-param>
		<init-param>
			<param-name>
				allowGetForSafariButMakeForgeryEasier
			</param-name>
			<param-value>true</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>
	

  <servlet-mapping>
		<servlet-name>dwr-invoker</servlet-name>
		<url-pattern>/dwr/*</url-pattern>
	</servlet-mapping>
	

	

java代码就是一个普通的操作String的工具类