при переходе на новую стр сбрасывается сортировка. подскажите где проглядел
вот форма

$text ="<div id='vt_navi_box' width=574px><center><table><tr><td>";
$text .="<a href='".e_PLUGIN."vtrade/vtrade.php?page=frontpage'>".VT_BUT_BEGIN." </a> ";
$text .="| <a href='".e_PLUGIN."vtrade/vtrade.php?page=categories&cat=0'>Весь товар </a> ";
//$text .="| <a href='".e_PLUGIN."vtrade/vtrade.php?page=search'>Поиск товара </a>";
//$text .="| <a href='".e_PLUGIN."vtrade/vtrade.php?page=basket'>".VT_BUT_BASK." </a>";
$_SESSION['sorting'];
$text .="<td><form enctype='multipart/form-data' name='form_sorting' method='post' action='". $PHP_SELF ."'>";
$text .=" <select name='sorting'>";
$text .="<option value=''>Сортировка товара</option>";
$text .="<option value='ORDER BY `nom_price1` ASC '>По возрастанию цены</option>";
$text .="<option value='ORDER BY `nom_price1` DESC'>По убыванию цены</option>";
$text .="<option value=''>По возрастанию наименования</option>";
$text .="<option value=''>По убыванию наименования</option>";
$text .="</select><input type='submit' style='cursor:pointer;' value='Сортировать' name='submit_sorting'>";
$text .="</form></td></tr></table>";
$text .="</center></div>";

а вот так выдергиваю

if (IsSet($cat) && $cat <> 0) {
	$text .="<div id='vt_cat_desc_block'>";
	$vtsql = new db;
	$vtsql -> db_Select("vt_cat", "*", "cat_id='$cat'");
	while($row = $vtsql -> db_Fetch()){
		$cat_name = $row['cat_name'];
		$cat_id = $row['cat_id'];
		$cat_img = $row['cat_img'];
		$cat_desc = $row['cat_desc'];
		if ($cat_img == '') {
			$cat_img = 'nom_empty.png';
		}
	$text .= "<table><tr><td>";
//	$text .= "<font size=1 color=#00d400><h1>$cat_name</h1></font>";
	$parseBB = $tp->toHTML($cat_desc,true,'body');
	$text .= "<img src='vt_pictures/category/$cat_img' alt='$cat_name' style='width:200px; float:left;'>";
	$text .= "<div id='vt_but_desc_block_up'><a href=# onclick=\"document.getElementById('vt_cat_desc_block').style.height='100%'; return false;\"><img src='theme/but_desc_block_up.png' align=right></a></div>";
	$text .= "<br><div id='vt_short_cat_desc'>$parseBB<br></div><br>";
	$text .= "<div id='vt_but_desc_block_down'><a href=# onclick=\"document.getElementById('vt_cat_desc_block').style.height='200px'; return false;\"><img src='theme/but_desc_block_down.png' align=right></a></div>";
	
//	$text .= "<div id='vt_cat_desc_block'>$parseBB<br><a href=# onclick=\"document.getElementById('vt_cat_desc_block').style.display='none'; return false;\"><img src='theme/but_desc_none.png' align=right></a></div>";
	$caption_section = " - <a href='".e_PLUGIN."vtrade/vtrade.php?page=categories&cat=$cat'>$cat_name</a>";
	}
	$text .="</td></table> </div>";
	
	$vtsql2 = new db;
	$vtsql2 -> db_Select("vt_nom", "*", "nom_id in (SELECT `index_nomid` FROM ".MPREFIX."vt_index WHERE index_catid='$cat') $sorting LIMIT $from,$conf_showrowsitems");
}

страницы формируються вот так

$vtsql1 = new db;
if (IsSet($cat) && $cat <> 0) $total_items = $vtsql1 -> db_Select("vt_index", "*", "index_catid='$cat'");
if (IsSet($cat) && $cat == 0) $total_items = $vtsql1 -> db_Select("vt_nom", "*", "");
$from = ($_GET['num_page']) ? $_GET['num_page'] : 0;
if ($total_items>$conf_showrowsitems){
$text .= "<div id='vt_block'><div id='vt_num_navi'>";
	$vtsql2 = new db;
	$vtsql2 -> db_Select("vt_cat", "*", "cat_id='$cat'");
	while($row = $vtsql2-> db_Fetch()){
	    $showcat = $row['cat_sub'];
	    $showcatname = $row['cat_name'];
	}
 $parms = $total_items.",".$conf_showrowsitems.",".$from.",".e_SELF."?page=categories&cat=".$cat."&num_page=[FROM]&showcat=".$showcat."";
 $text .= $tp->parseTemplate("{NEXTPREV={$parms}}");
 $text .= "</div></div>";
}