<?php
$Keywd=htmlspecialchars($_GET['key']);
$Keywd=mb_convert_encoding($Keywd,"auto");
$Keywd=mb_convert_kana($Keywd,"s", EUC-JP");
$Keywd=ereg_replace("and"," ",$Keywd);
$Keywd=ereg_replace(" "," ",$Keywd);
$Data=file("item.csv");
?>

<?php
if($Keywd!=""){
$Result = array();
for($n=0;$n<sizeof($Data);$n++){
$line=explode(",",$Data[$n]);
$arrSentence = strip_tags($Data[$n]);
$arrKeyword = explode(" ",$Keywd);
for($i=0; $i<sizeof($arrKeyword); $i++) {
$flgMatched = true;
if(!eregi($arrKeyword[$i], $arrSentence)) {
$flgMatched = false;
break;
.......
if($flgMatched) {
array_push($Result, $Data[$n]);
..

コピペだけどこっちのほうがいいんじゃない？