Investigating jQuery

So, you have a bunch of HTML elements. Let's say they're Fieldsets.

view plainprint?

1. <fieldset>  
2.   <legend> x </legend>  
3.   XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX  
4. </fieldset>  
5. <fieldset>  
6.   <legend> x </legend>  
7.   XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX  
8. </fieldset>  
9. <fieldset>  
10.   <legend> x </legend>  
11.   XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX  
12. </fieldset>  

  
 x 
  XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX


  
 x 
  XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX


  
 x 
  XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX

Now, you want to be able to hide some of those fieldsets. You could make the legend clickable.

view plainprint?

1. <fieldset id="target">  
2.   <legend onclick="hide_element('target')"> x </legend>  
3.   XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX  
4. </fieldset>  

  
 x 
  XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX

hide_element() is dead easy. I do it in five lines. I could drop one if I wanted. Just a bit of stylesheet manipulation. But there's a problem. As written, that hides the fieldset for good. I really want to toggle. So, something must remain.

view plainprint?

1. <fieldset>  
2.   <legend onclick="hide_element('target')"> x </legend>  
3.   <div id="target"> XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX </div>  
4. </fieldset>  

  
 x 
  
 XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX 

This is better, but you have to name every single fieldset. There should be a way to address everything anonymously. And there is. jQuery. Which I don't quite grok yet. But that's where my head is.