Probleme beim download eines eigenen Export

function participant_export($export_event_id){
    $suche = array('"', ';');
    $ersetzen = array("'", " ");
    
    $result = mysql_query("SELECT name_text, name_anonym_table_text, number_table_text, website_text, free1_text, free2_text, free3_text, free4_text, free5_text, free6_text, free7_text, age_title, select_text FROM wp_lop3_head where `entry_var` = '".$export_event_id."'");
    if (@ mysql_num_rows($result) != 0) {
        while ($daten = mysql_fetch_assoc($result)) {
            if (is_array($daten) == true) {
                foreach ($daten as $key => $value) {
                    $ausgabe .= str_replace($suche, $ersetzen, $daten[$key]).";";
                }
            }
        $ausgabe .= "rn";
       }
    } 
      
    $result = mysql_query("SELECT participants, name_anonym, number, website, free1, free2, free3, free4, free5, free6, free7, age_timestamp, select_var FROM `wp_lop3` where `entry_var` = '".$export_event_id."'"); 
    if (@ mysql_num_rows($result) != 0) {
        while ($daten = mysql_fetch_assoc($result)) {
            if (is_array($daten) == true) {
                foreach ($daten as $key => $value) {
                    $ausgabe .= str_replace($suche, $ersetzen, $daten[$key]).";";
                }
            }
        $ausgabe .= "rn";
       }
    }else {
       $ausgabe .= "Es sind keine Daten in der Tabelle vorhanden!;";
    }        
     
    if (headers_sent() == false) {
        header("Content-type: text/csv");    
        header('Expires: ' . gmdate('D, d M Y H:i:s') . ' GMT');    
        header('Content-Disposition: attachment; filename=download.csv');
        header('Pragma: no-cache');
    }
    
    echo $ausgabe;
}