php去除html标记

<? 
function Text2Html($txt){ 
        $txt = str_replace("  "," ",$txt); 
        $txt = str_replace("<","<",$txt); 
        $txt = str_replace(">",">",$txt); 
        $txt = preg_replace("/[rn]{1,}/isU"," 
rn",$txt); 
        return $txt; 
} 

?>