เรื่องการตัดคำอะคับ มัน error ดูไห้ผมหน่อยคับ ผมมีโค้ดมาไห้ดูคับ Fatal error: Cannot redeclare substr_unicode()

<?
function substr_unicode($str, $s, $l = null) {
    return join("", array_slice(
        preg_split("//u", $str, -1, PREG_SPLIT_NO_EMPTY), $s, $l));
}
?>

<?
				  include ("conne.php");
 $sql1="select iv_date from iv_kool   ORDER BY iv_date DESC "; 
	$Qtotal1 = mysql_query($sql1);
     $qr1 =@mysql_db_query(koolsport_dashboard,$sql1) or die("error $sql1");
$rs1=mysql_fetch_array($qr1);
$amount1 = $rs[amount];
$iv_date1 = $rs[iv_date];
function substr_unicode($str, $s, $l = null) {
return join("", array_slice(preg_split("//u", $str, -1, PREG_SPLIT_NO_EMPTY), $s, $l));        
} // บรรทัดที่ 108
$str = "$iv_date1";
$s = 0; // start from "0" (nth) char
$l = 2; // get "3" chars
echo substr($str, $s, $l) ."\n";    // Bü
echo mb_substr($str, $s, $l) ."\n"; // Bü
echo substr_unicode($str, $s, $l);  // Büy
?>