php过滤html字符串，防止SQL注入

//php 批量过滤post,get敏感数据
	if (get_magic_quotes_gpc()) {
	$_GET = stripslashes_array($_GET);
	$_POST = stripslashes_array($_POST);
	}
	
	function stripslashes_array(&$array) {
	while(list($key,$var) = each($array)) {
	if ($key != 'argc' && $key != 'argv' && (strtoupper($key) != $key || ''.intval($key) == "$key")) {
	if (is_string($var)) {
	$array[$key] = stripslashes($var);
	}
	if (is_array($var))  {
	$array[$key] = stripslashes_array($var);
	}
	}
	}
	return $array;
	}
          //--------------------------

	// 替换HTML尾标签,为过滤服务
	//--------------------------
	function lib_replace_end_tag($str)
	{
	if (empty($str)) return false;
	$str = htmlspecialchars($str);
	$str = str_replace( '/', "", $str);
	$str = str_replace("\", "", $str);
	$str = str_replace("&gt", "", $str);
	$str = str_replace("&lt", "", $str);
	$str = str_replace("<SCRIPT>", "", $str);
	$str = str_replace("</SCRIPT>", "", $str);
	$str = str_replace("<script>", "", $str);
	$str = str_replace("</script>", "", $str);
	$str=str_replace("select","select",$str);
	$str=str_replace("join","join",$str);
	$str=str_replace("union","union",$str);
	$str=str_replace("where","where",$str);
	$str=str_replace("insert","insert",$str);
	$str=str_replace("delete","delete",$str);
	$str=str_replace("update","update",$str);
	$str=str_replace("like","like",$str);
	$str=str_replace("drop","drop",$str);
	$str=str_replace("create","create",$str);
	$str=str_replace("modify","modify",$str);
	$str=str_replace("rename","rename",$str);
	$str=str_replace("alter","alter",$str);
	$str=str_replace("cas","cast",$str);
	$str=str_replace("&","&",$str);
	$str=str_replace(">",">",$str);
	$str=str_replace("<","<",$str);
	$str=str_replace(" ",chr(32),$str);
	$str=str_replace(" ",chr(9),$str);
	$str=str_replace("    ",chr(9),$str);
	$str=str_replace("&",chr(34),$str);
	$str=str_replace("'",chr(39),$str);
	$str=str_replace("<br />",chr(13),$str);
	$str=str_replace("''","'",$str);
	$str=str_replace("css","'",$str);
	$str=str_replace("CSS","'",$str);
	
	return $str;
	
	}

引用是直接这样： $xxx = htmlspecialchars($_POST['xxx']); 
或者 $xxx = htmlspecialchars($_GET['xxx']);