title: Remove or add item from list in scala
body: <p>Each time check box clicked appropraite id is passed to check method.. </p>
  
  <pre><code>  @RequestMapping(value = Array("checkBoxCheck.html"))
        @ResponseBody
        def check(@RequestParam checkBoxId: Long) {
        processing(checkBoxId) 
  
        }
  
      def processing(checkBoxId:Long){....}
  </code></pre>
  
  <p>the above code is example of spring scala..
  i want to add each id to a list ,if it is  exists already remove it from the list in  processing method</p>