PHP Thumbnail photoalbum

[chataqua]

I have a little problem. I've just coded a photoalbum, where the code is like this;
<?PHP
$current=$HTTP_SERVER_VARS['QUERY_STRING'];
$theavis="theavis.php?".$current;
$theatumb="http://home.online.no/~hoegaard/thea-tumb/thea".$current.".jpg";
echo'<a href="';
echo $theavis;
echo'" target="_blank"><img src ="';
echo $theatumb;
echo '" border="0" </a>';
$forrige = $current -1;
$neste = $current +1;
echo"</TD></TR>";
?>

This works fine. The page is viewing one picture at the time, which is how I will have it. My problem is that I, as of now, only can view the first and the last photo in the album using theese codes:
<a href='theafoto.php?1'>First Picture</a>
and
<a href='theafoto.php?61'>Last Picture</a>

Now I want to have a next and previous link, now I have theese links like this (I know this is all wrong, it don't work):
echo'<a href=';echo $neste;echo'>';Next Picture</a>
and
echo'<a href=';echo $forrige;echo'>';Previous Picture</a>

This don't work, but I don't know what to write instead..
Could somebody help me??

[chataqua]

Forget it, found it out by myself......

[milind24]

also check this :

if(!$current || !isset($current) || empty($current))
	$current=1;
$maxlimit = 100;
$theavis="theavis.php?current=".$current; 
$theatumb="http://home.online.no/~hoegaard/thea-tumb/thea".$current.".jpg"; 
echo'<a href="'; 
echo $theavis; 
echo'" target="_blank"><img src ="'; 
echo $theatumb; 
echo '" border="0" </a>'; 
$forrige = $current -1; 
$neste = $current +1; 
echo"</TD></TR>"; 
print "<br>";
if($current > 1)
	print "<a href=".$PHP_SELF."?current=".$forrige.">Previous Picture</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"; 
if($current < $maxlimit)
print  "<a href=".$PHP_SELF."?current=".$neste.">Next Picture</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;";