php bilen yardım edebilirmi ?

<?php
$title =  $pages[$cur_page]["Name"]." - ".HCSGP_DEFTITLE;
$durum = FALSE;
$message = '';

function karakterDuzelt($yazi){
    $ara=array("ç","i","ı","ğ","ö","ş","ü");
    $degistir=array("Ç","İ","I","Ğ","Ö","Ş","Ü");
    $yazi=str_replace($ara,$degistir,$yazi);
    $yazi=strtoupper($yazi);
    return $yazi;
}

if( isset($_POST["ogcp_adduser"]) ) {
    $_POST["user_group"] = 1;
        if(@$_POST["user_email"] != "" && @$_POST["user_year"] != "" && @$_POST["user_lastname"] != "" && @$_POST["user_tc"] != "" && @$_POST["user_pass"] != "" && @$_POST["user_name"] != "" && @$_POST["user_city"] != "" && @$_POST["user_address"] != "" && @$_POST["user_telephone"] != "" && (int)@$_POST["user_group"] > 0 && (int)@$_POST["user_group"] < 4) {

                $_POST["ShowMachine"] = 0;
                $_POST["ShowServers"] = 0;
                $_POST["ShowUsers"] = 0;
                $_POST["ShowAnnouncements"] = 0;
                $_POST["ShowTickets"] = 0;
                $_POST["ShowPlugins"] = 0;
                $_POST["ShowFiles"] = 0;
            
            if (!filter_var($_POST["user_email2"], FILTER_VALIDATE_EMAIL)) {
                $message = "Geçerli bir Email Adresi girin!";
            }
            else{
                $ad = karakterDuzelt(trim($_POST["user_name"]));
                $soyad = karakterDuzelt(trim($_POST["user_lastname"]));
                $tcKimlikNo = $_POST["user_tc"];
                $dogumYili = $_POST["user_year"];

                function tcno_dogrula($bilgiler){
                    $gonder = '<?xml version="1.0" encoding="utf-8"?>
                    <soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
                    <soap:Body>
                    <TCKimlikNoDogrula xmlns="http://tckimlik.nvi.gov.tr/WS">
                    <TCKimlikNo>'.$bilgiler["tcno"].'</TCKimlikNo>
                    <Ad>'.$bilgiler["isim"].'</Ad>
                    <Soyad>'.$bilgiler["soyisim"].'</Soyad>
                    <DogumYili>'.$bilgiler["dogumyili"].'</DogumYili>
                    </TCKimlikNoDogrula>
                    </soap:Body>
                    </soap:Envelope>';

                    $ch = curl_init();
                    curl_setopt($ch, CURLOPT_URL,            "https://tckimlik.nvi.gov.tr/Service/KPSPublic.asmx" );
                    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true );
                    curl_setopt($ch, CURLOPT_POST,           true );
                    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
                    curl_setopt($ch, CURLOPT_HEADER, FALSE);
                    curl_setopt($ch, CURLOPT_POSTFIELDS,    $gonder);
                    curl_setopt($ch, CURLOPT_HTTPHEADER,     array(
                    'POST /Service/KPSPublic.asmx HTTP/1.1',
                    'Host: tckimlik.nvi.gov.tr',
                    'Content-Type: text/xml; charset=utf-8',
                    'SOAPAction: "http://tckimlik.nvi.gov.tr/WS/TCKimlikNoDogrula"',
                    'Content-Length: '.strlen($gonder)
                    ));
                    $gelen = curl_exec($ch);
                    curl_close($ch);

                    return strip_tags($gelen);
                }

                $bilgiler = array(
                "isim"      => $ad,
                "soyisim"   => $soyad,
                "dogumyili" => $dogumYili,
                "tcno"      => $tcKimlikNo
                );
                $adsoyad = $_POST["user_name"]." ".$_POST["user_lastname"];

                $sonuc = tcno_dogrula($bilgiler);

                if($sonuc=="true"){
                    $status = Adm_AddUser($tcKimlikNo,$_POST["user_email"],$_POST["user_email2"],$_POST["user_comment"],$_POST["user_pass"],$adsoyad,$_POST["user_city"],$_POST["user_address"],$_POST["user_telephone"],$_POST["user_group"],$_POST["ShowMachine"],$_POST["ShowServers"],$_POST["ShowUsers"],$_POST["ShowAnnouncements"],$_POST["ShowTickets"],$_POST["ShowPlugins"],$_POST["ShowFiles"]);    
                    
                    if($status > 0) {
                    $message = "Kayıt Başarılı! Yönlendiriliyorsunuz..";    
                    echo '<meta http-equiv="refresh" content="1;URL='.$page->CreatePageLink('Giris').'" />';
                    } else if($status == -1){
                        $message = "Böyle bir kullanıcı sistemde mevcut!!";
                    } else {
                        $message = "Hata Oluştu!";
                    }
                }
                else{
                    $message = "Girilen Kimlik Bilgileri Uyuşmuyor!";
                }

            }        
            
        } else {
            $message = "Alanları Kontrol Edin!";
        }
    }

kayit.php bu

<?php
    if( isset($_POST["ogcp_adduser"]) ) {
        if(@$_POST["user_email"] != "" && @$_POST["user_pass"] != "" && @$_POST["user_name"] != "" && @$_POST["user_city"] != "" && @$_POST["user_address"] != "" && @$_POST["user_telephone"] != "" && (int)@$_POST["user_group"] > 0 && (int)@$_POST["user_group"] < 4) {
            if($_POST["user_group"] == 3) {
                $_POST["ShowMachine"] = 1;
                $_POST["ShowServers"] = 1;
                $_POST["ShowUsers"] = 1;
                $_POST["ShowAnnouncements"] = 1;
                $_POST["ShowTickets"] = 1;
                $_POST["ShowPlugins"] = 1;
                $_POST["ShowFiles"] = 1;
            } else if($_POST["user_group"] == 1) {
                $_POST["ShowMachine"] = 0;
                $_POST["ShowServers"] = 0;
                $_POST["ShowUsers"] = 0;
                $_POST["ShowAnnouncements"] = 0;
                $_POST["ShowTickets"] = 0;
                $_POST["ShowPlugins"] = 0;
                $_POST["ShowFiles"] = 0;
            }
            $status = Adm_AddUser($_POST["user_email"],$_POST["user_email2"],$_POST["user_comment"],$_POST["user_pass"],$_POST["user_name"],$_POST["user_city"],$_POST["user_address"],$_POST["user_telephone"],$_POST["user_group"],$_POST["ShowMachine"],$_POST["ShowServers"],$_POST["ShowUsers"],$_POST["ShowAnnouncements"],$_POST["ShowTickets"],$_POST["ShowPlugins"],$_POST["ShowFiles"]);
            if($status > 0) {
                $page->GoLocation($page->CreatePageLink('Adm_Kullanici_Duzenle','ID='.$status));
            } else if($status == -1){
                echo "Kullanıcı adı kullanılıyor!";
            } else {
                echo "Kullanıcı Eklenemedi!";
            }
        } else {
            echo "Alanları kontrol ediniz!";
        }
    }
?>

adm kullanıcı eklede budur arkadaşlar
ben şimdi sisteme aynı tc kimlikli kişinin tekrar üye olamayıp böyle bir kullanıcı sistemde mevcut bastırmak istiyorum bunu nasıl yapabilirim ?

function Adm_AddUser($tckimlik,$Email,$Email2,$Comment,$Pass,$Name,$City,$Address,$Telephone,$Group,$Machine,$Servers,$Users,$Announ,$Tickets,$Plugins,$Files) {
    if( $Email == "" || $Pass == "" || $Name == "" || $City == "" || $Address == "" || $Telephone == "" || (int)$Group <= 0 || (int)$Group > 3 ) return false;
    global $__HCSGPMYSQL;
    if( Adm_ControlUserEmail($Email) === true) return -1;
    if( Adm_ControlUserEmail2($Email2) === true) return -1;
    $sql_query = "INSERT INTO `ogcp_users` (`UserEmail`, `UserPassword`, `UserEmail2` , `UserComment`,`UserName`,`UserTc`, `UserCity`, `UserAddress`, `UserTelephone`, `UserGroup`, `UserLastLogin`, `ShowMachine`, `ShowServers`, `ShowUsers`, `ShowAnnouncements`, `ShowTickets`, `ShowPlugins`, `ShowFiles`) VALUES ('".addslashes($Email)."','".md5(md5($Pass))."', '".addslashes($Email2)."', '".addslashes($Comment)."', '".addslashes($Name)."','".addslashes($tckimlik)."', '".addslashes($City)."', '".addslashes($Address)."', '".addslashes($Telephone)."', '".(int)$Group."', 0, '".(int)$Machine."','".(int)$Servers."','".(int)$Users."','".(int)$Announ."','".(int)$Tickets."','".(int)$Plugins."','".(int)$Files."')";
    $sql_query = $__HCSGPMYSQL->query($sql_query);
    if($sql_query == false) return 0; else return $__HCSGPMYSQL->lastInsertId();
}

buda adm adduser fonksiyonu

Üye eklemeden önce Select sorgusu açıp posttan gelen tcyi sorgulattır. Kayıt varsa Üyeyi eklemeden geri dönsün.