<?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?>