<style>
a {color:red; display:block}
.active {color:black; font-weight: bold; }
.a {font-size:30px;}
</style>

<a href='test.php?x=1'>test.php</a>
<a href='test.php?x=2'>test.php</a>
<a href='test.php?x=3'>test.php</a>
<a href='test.php?x=4'>test.php</a>
<a href='test.php?x=5'>test.php</a>
<a href='test.php?x=6'>test.php</a>
<a href='test.php?x=7' class='a'>test.php</a>
<a href='test.php?x=8'>test.php</a>


<script>
(function(){
    for (var i = 0, x; x = document.links[i]; ++i) {
        if ('' + x == '' + window.location) 
            x.className += ' active';
    }
})();
</script>