<select name="month" id="month">
<option value="1">январь</option>
<option value="2">февраль</option>
<option value="3">март</option>
<option value="4">апрель</option>
<option value="5">май</option>
<option value="6">июнь</option>
<option value="7">июль</option>
<option value="8">август</option>
<option value="9">сентябрь</option>
<option value="10">октябрь</option>
<option value="11">ноябрь</option>
<option value="12">декабрь</option>
</select>

INSERT INTO <название таблицы> ([<Имя столбца>, ... ]) VALUES (<Дата рождения>,<пол>)

if(sendmail($email,$subject,$message,$headers) !== FALSE) {    
                    echo "<meta http-equiv=\"Refresh\" content=\"0; url=andy123.php">";    
                  }

<meta http-equiv="content-type" content="text/html; charset=windows-1251">

if(sendmail($email,$subject,$message,$headers) !== FALSE) {    
                    header("Location: index.php");   
                  }

if(sendmail($email,$subject,$message,$headers) !== FALSE) {    
                   header("Request-URI: index.php");
                  }

if(sendmail($email,$subject,$message,$headers) !== FALSE) {    
                    header("Content-Location: index.php");
                  }

if(sendmail($email,$subject,$message,$headers) !== FALSE) {    
                    echo "<script type=\"text/javascript\"> document.location.href = \"index.php\";  </script>";    
                  }

if(sendmail($email,$subject,$message,$headers) !== FALSE) {   
                   echo "<meta http-equiv=\"Refresh\" content=\"0; url=index.php\">";   
                 }