Fixed position but relative to container

Question

I am trying to fix a div so it always sticks to the top of the screen, using:

position: fixed;
top: 0px;
right: 0px;

However,

Answer 1

This is easy (as per HTML below)

The trick is to NOT use top or left on the element (div) with "position: fixed;". If these are not specified, the "fixed content" element will appear RELATIVE to the enclosing element (the div with "position:relative;") INSTEAD OF relative to the browser window!!!

    

        

            
                X
            
        
    
    
  
         lots of Text To Be Scrolled vertically...
         bhah! blah! blah!
    

Above allowed me to locate a closing "X" button at the top of a lot of text in a div with vertical scrolling. The "X" sits in place (does not move with scrolled text and yet it does move left or right with the enclosing div container when the user resizes the width of the browser window! Thus it is "fixed" vertically, but positioned relative to the enclosing element horizontally!

Before I got this working the "X" scrolled up and out of sight when I scrolled the text content down.

Apologies for not providing my javascript hideDiv() function, but it would needlessly make this post longer. I opted to keep it as short as possible.