$str=preg_replace("/\s+/", " ", $str); //过滤多余回车

$str=preg_replace("/

$str=preg_replace("//si","",$str); //注释

$str=preg_replace("//si","",$str); //过滤DOCTYPE

$str=preg_replace("//si","",$str); //过滤html标签

$str=preg_replace("//si","",$str); //过滤head标签

$str=preg_replace("//si","",$str); //过滤meta标签

$str=preg_replace("//si","",$str); //过滤body标签

$str=preg_replace("//si","",$str); //过滤link标签

$str=preg_replace("//si","",$str); //过滤form标签

$str=preg_replace("/cookie/si","COOKIE",$str); //过滤COOKIE标签

$str=preg_replace("/(.*?)/si","",$str); //过滤applet标签

$str=preg_replace("//si","",$str); //过滤applet标签

$str=preg_replace("/(.*?)/si","",$str); //过滤style标签

$str=preg_replace("//si","",$str); //过滤style标签

$str=preg_replace("/(.*?)/si","",$str); //过滤title标签

$str=preg_replace("//si","",$str); //过滤title标签

$str=preg_replace("/(.*?)/si","",$str); //过滤object标签

$str=preg_replace("//si","",$str); //过滤object标签

$str=preg_replace("/(.*?)/si","",$str); //过滤noframes标签

$str=preg_replace("//si","",$str); //过滤noframes标签

$str=preg_replace("/(.*?)/si","",$str); //过滤frame标签

$str=preg_replace("//si","",$str); //过滤frame标签

$str=preg_replace("/(.*?)/si","",$str); //过滤script标签

$str=preg_replace("//si","",$str); //过滤script标签

$str=preg_replace("/javascript/si","Javascript",$str); //过滤script标签

$str=preg_replace("/vbscript/si","Vbscript",$str); //过滤script标签

$str=preg_replace("/on([a-z]+)\s*=/si","On\\1=",$str); //过滤script标签

$str=preg_replace("//si","&＃",$str); //过滤script标签，如javAsCript:alert(