MySQL database dump creator - PHP

<?php
function mysqldump($DBhost,$DBuser,$DBpass,$DBname,$tables = '*'){
    $connect = mysql_connect($DBhost,$DBuser,$DBpass);
    mysql_select_db($DBname,$connect);
    if($tables == '*'){
        $tables = array();
        $result = mysql_query('SHOW TABLES');
        while($row = mysql_fetch_row($result)){
            $tables[] = $row[0];
        }
    }
    else{
        $tables = is_array($tables) ? $tables : explode(',',$tables);
    }
    if(!is_array($tables))$tables[] = $tables;
    foreach($tables as $table){
        $return .= "\n\n-- DUMPING TABLE $table --";
        $result = mysql_query('SELECT * FROM '.$table);
        $num_fields = mysql_num_fields($result);
        $return .= "\n\nDROP TABLE IF EXISTS `".$table."`;";
        $row2 = mysql_fetch_row(mysql_query("SHOW CREATE TABLE ".$table));
        $return .= "\n\n".$row2[1].";";
        for($i=0;$< $num_fields; $i++){
            while($row = mysql_fetch_row($result)){
                $return.= "\n\nINSERT INTO `".$table."` VALUES (";
                    for($j=0; $j<$num_fields; $j++){
                        $row[$j] = addslashes($row[$j]);
                        $row[$j] = preg_replace("@\n@","\\n",$row[$j]);
                        if(isset($row[$j])){ $return.= '"'.$row[$j].'"';}
                        else{$return.= '""';}
                        if ($j<($num_fields-1)){$return.= ',';}
                    }
                $return.= ");";
            }
        }
        $return .= "\n\n";
    }
    file_put_contents('tech-db-backup-'.time().'.sql',$return);
}
?>