INSERTING DATA FROM A FORM

I am using mysql and php to design a book review website however I can not get this code to work and have less then 24 hours to sort this code out and the code for the post I will post following this. If any one can help me I would be very greatful.
<?php



if ($submit) {

// process form

$db = mysql_connect("localhost", "root");

mysql_select_db("fantasybooks",$db);

$sql = "INSERT INTO review (User_name, Review_number Review_date, Review) VALUES ('$User_name',$Review_number,'$Review_date','$Revi ew')";
$result = mysql_query($sql);

echo ?><BR><BR><BR><A href= Selection.php>Options Screen</a><?
?>

<?

} else{



// display form



?>



<form method="post" action="<?php echo $PHP_SELF?>">

User:<input type="Varchar" name="User_name" size = "50"><br>

Review_number:<input type="Varchar" name="Review_number" size ="3"><BR>

Review_date:<input type="Varchar" name="Review_date" ><br>

Review:<input type="Varchar" name="Review" size = "255"><br>

<input type="Submit" name="submit" value="Enter information">

</form>



<?php



} // end if



?>



</body>



</html>