Highlighting a Tab

OK, I am completely lost and seek desperate help!

I am porting a theme that uses <a> tag to decide if it’s current or not (instead of using the <li> tag), if it is, then it highlights the tab.

this is the CSS code:

#tabsgp { background: #fff url(img/bigbox.gif) no-repeat top left; color: #000; height: 64px; text-align: center; padding: 0 0 0 248px; }
#tabsgp li { display: inline; height: 45px; }
#tabsgp li a { float: left; background: #fff url(img/barbg.gif) no-repeat; color: #808080; padding: 7px 0; width: 82px; text-align: center; font-weight: bold; text-decoration: none; }
#tabsgp li a:hover { background: #fff url(img/barcurrent.gif) no-repeat; color: #000; }
#tabsgp li a.current { background: #fff url(img/barcurrent.gif) no-repeat; color: #2C71AE; }
.key { text-decoration: underline; }

how can I make it so it recognizes li tag with the “current_page_nav”?

I tried converting it to recognize li tag, but it broke the tab system down.

any help appreciated ??

Thanks,
-LR