Create Directory

<?php
try{
    if(file_exists("files/$username")){
        $rand = substr(md5(microtime()),rand(0,26),5);
        if(mkdir("files/$username.$rand", 0777))
        {
            return true;
        }else{
            throw new Exception('Cant create directory');
        }
    }else{
        if(mkdir("files/$username", 0777))
        {
            return true;
        }else{
            throw new Exception('Cant create directory');
        }
    }
}catch(Exception $e){
    echo $e->getMessage();
}
?>