PHP把全角数字转为半角数字以及去除HTML标

//把全角数字转为半角数字
<?
function GetAlabNum($fnum){
        $nums = array("０","１","２","３","４","５","６","７","８","９");
        $fnums = "0123456789";
        for($i=0;$i<=9;$i  ) $fnum = str_replace($nums[$i],$fnums[$i],$fnum);
        $fnum = ereg_replace("[^0-9.]|^0{1,}","",$fnum);
        if($fnum=="") $fnum=0;
        return $fnum;
}

?>

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