$rs= mysql_query("select * from cxjb2 where nam ".$_POST[select3]." $_POST[nam] and cat ".$_POST[select0]." $_POST[cat] and sha ".$_POST[select1]." $_POST[sha] and pri is NULL or nam ".$_POST[select3]." $_POST[nam] and cat ".$_POST[select0]." $_POST[cat] and sha ".$_POST[select1]." $_POST[sha]");
$rs= mysql_query("select * from cxjb2 where nam