<?if($PAGE_ID$='threadpage')?>       
<script type="text/javascript">       
function go(){       
page=$('#gopage').val(); // X-3me ~  http://x-3me.ru       
ftid=location.href.split('/')[4];       
fid=ftid.split('-')[0];       
tid=ftid.split('-')[1];       
document.location.assign('/forum/'+fid+'-'+tid+'-'+page);       
}       
</script>       
<form>       
На страницу:          
<input id="gopage" type="text">          
<input value="Перейти" onclick="go();" type="button">          
</form>       
<?endif?>