Like I said before, there isn't much you can do with the code you have except change the CSS in the background_image class.
But also as I said before it won't work in IE.
But what you can do is copy my code into a simple text editor and save it as a plain text file with a .html extension.
The page I created for you will work with your other pages.
If you look at these two lines of code, this is where the navigation links go.
You just need to create a line like these for each navigation link you want to insert.
And then add the CSS in the style section for the new link.
Like I have for these two links.
Or you could use these two classes.
.side_content_1 if for plain text and .side_content_2 is for bold text.
CSS Code:
.side_content_1
{
background:#CCFF66;
height:25px;
padding-left:22px;
padding-top:1px;
cursor:pointer;
}
.side_content_2
{
background:#CCFF66;
height:26px;
padding-left:22px;
font-weight:bold;
cursor:pointer;
}