maven jetty plugin does not rebuild war

[tubin gen <fa...@gmail.com>]

maven plugin   in my pom

        <plugin>
            <groupId>org.mortbay.jetty</groupId>
            <artifactId>jetty-maven-plugin</artifactId>
            <version>7.0.0.pre5</version>
            <configuration>
                <contextPath>/audit</contextPath>
                <jettyEnvXml>${basedir}/jetty-env.xml</jettyEnvXml>
            </configuration>
           <dependencies>
              <dependency>
                  <groupId>commons-dbcp</groupId>
                  <artifactId>commons-dbcp</artifactId>
                  <version>1.2.2</version>
                  <scope>compile</scope>
              </dependency>
              <dependency>
                  <groupId>com.oracle</groupId>
                  <artifactId>ojdbc</artifactId>
                  <version>14</version>
                  <scope>compile</scope>
              </dependency>
           </dependencies>
        </plugin>
    </plugins>


any time I make changes to java code and   run jetty:run the changes are not
picked up , I have to do a clean and which deletes the war file , if there
is war file in target   then this plugin does not rebuild the war , please
help me how to resolve this ?