registrazione utente

[fcfclean]

salve non riesco a configurare i file della registrazione utente vorrei che quando si inserisce la data di nascita es: 01/01/2019 il controllo della data e i dati inseriti chiedo aiuto grazie
--------------------------------------------
Form

<form id="login_form1" action="singupc.php" class="form-signin" method="post">
<h3 class="form-signin-heading">
<i class="icon-lock"></i> Please Sing Up
</h3>
<input type="text" class="input-block-level" name="firstname" placeholder="First_name" required>
<input type="text" class="input-block-level" name="lastname" placeholder="Last_name" required>
<input type="text" class="input-block-level" id="username" name="username" placeholder="User_name" required>
<input type="password" class="input-block-level" id="password" name="password" placeholder="Pasword" required>

<h4>birth:</h4>
<input type="text" class="input-block-level" id="checkdate" name="birth" placeholder="gg/mm/yy" required>
<table>
<tr>
<td>
<h4>Gender</h4>
</td>
</tr>
<td>
<input type="radio" name="gender" value="male" required />Male
</td>
<td>
<input type="radio" name="gender" value="female" required />Female
</td>
</table>
<h4>----</h4>



<button data-placement="right" title="Click Here to Sign up" id="signin" name="singup" class="btn btn-info" type="submit"><i class="icon-signup icon-large"></i> Sign up</button>

---------------------------------------
server
<?php
include('admin/lib/dbcon.php');
session_start();


if (isset($_POST['singup']))
{


$firstname=$_POST['firstname'];
$lastname=$_POST['lastname'];
$username=$_POST['username'];
$password=$_POST['password'];
$birth=$_POST['birth'];
$gender=$_POST['gender'];


$gg=$_POST['giorno'];
$mm=$_POST['mese'];
$yy=$_POST['anno'];



mySQL_query("INSERT INTO admin (firstname,lastname,username,password,birth,gender )
VALUES ('$firstname','$lastname','$username','$password', '$birth','$gender')")
or die (mySQL_error());
echo "<script>alert('Account successfully created!'); window.location='index.php'</script>";

?>

<?php } ?>

[fcfclean]

risolto :)