want to choose the css selector "clicked"

want to choose the css selector "clicked"

hello.  I have a question about choosing a css selector.
As partially shown below, an user clicks a dom element "dl dt", then the code executes whatever inside.

in the HTML, there is an element

<dl>

 <dt>...</dt>
   <dd>
    <div id="">...</div>
   </dd>

 <dt>...</dt>
  <dd>
   <div id="">...</div>
  </dd>
...
</dl>

then, by clicking "dl dt", the element works fine.  But I want as well to change the attribute of the div element, which is a child of <dl> and is a sibling of <dt> .

How should I set the selector in order to make $(...).attr("id", "slideShow") work fine?

//-----------------------------jQuery code-------------------------------------------
  $("dl dt").click(function(){
  if($("+dd", this).css("display")=="none"){
      $("dd").slideUp("slow");
      $("+dd", this).slideDown("slow");
      $("dt").removeClass("selected");
      $(this).addClass("selected");
 
//★★★★★HERE!
      $(this + "div").attr("id", "slideShow");
      
  }