使用Eclipse / Tomcat自动将第三方jar添加到WEB-INF / lib

I have a dynamic-web project set up on Eclipse and I'm using Tomcat 7 as my web server. It doesn't seem to be automatically putting 3rd party JARs I add to my library on my build path into the WEB-INF/lib folder. Is there a way I can do this automatically? Every time I search for an answer to this, I find something like I have a dynamic-web project set up on Eclipse