I got this code (below) from a web html tutorial and added it into my index page and my css file. And all that shows on the web page is CONTENT GOES HERE.
I guess I need a corner image named box-bg? Can you provide me with a corner image? And how do I add a light-grey, thin border around the box?
Can you help me create a border for this code?

thanks

In index page:
<div class="box">
 <div class="topleft">
   <div class="topright">
     <div>
       CONTENT GOES HERE
     </div>
   </div>
 </div>
 <div class="bottomleft">
 <div class="bottomright">
 </div>
 </div>
</div> 
and in CSS:
.box div.topleft {
     display: block;
     background: url("../images/box-bg.png") top left no-repeat white;
     padding: 2.0em 0em 0em 2.0em;
}
.box div.topright {
     display: block;
     background: url("../images/box-bg.png") top right no-repeat white;
     padding: 2.0em;
     margin: -2.0em 0 0 2.0em;
}
.box div.bottomleft {
     display: block;
     height: 45px;
     margin-top: -2.0em;
     background: url("../images/box-bg.png") bottom left no-repeat white;
}
.box div.bottomright {
     display: block;
     background: url("../images/box-bg.png") bottom right no-repeat white;
     height: 45px;
     margin-left: 3.0em;
}

That box-bg.png file should be downloaded from where you followed the tutorial. Also, here's the code you can add the CSS to have a border:

border: 1px solid #555;

ya...true you would get box-bg.png from the html tutorial site
In the code provided by you, they have used css sprites i.e. a ingle image is used to create a box with four corners.
Also, if you give border to the box, then you would lose the effect of the image used for styling the corners of the box as the border would create a total rectangular box surrounding your div. Still you can give a try

If you have forgotten the site, you could also use http://wigflip.com/cornershop/
Like in order to get a grey colored rounded corner box with white background they would provide you the css, html and images (dont forget the download the images and put on your server folder. You would probably need to change the css to update the location of the images