validate input from form???

[gk20]

I have a form where I accept an email from the user. I enter their username and email into a table called validate, and then validate the email to see whether it ends in a certain domain. If it does then I submit all the user details into the user table. If not, then $problem=true; etc...
Whether or not the email validation evaluates to true, I delete the entry i just added to the validate table
Heres my code:

$username = $_POST['username'];
$Email = $_POST['Email'];
......
$validatename = $_POST['username'];
$validateemail = $_POST['Email'];
.....

$insertval = "INSERT INTO validate SET
validatename = '$username',
validateemail = '$Email' ";


$emailval = @mysql_query("select validateemail from validate
where validateemail like '%student.example.com'
OR validateemail like '%EXAMPLE.IE'
OR validateemail like '%STAFF.EXAMPLE.COM'");

if (mysql_num_rows($emailval) == 1)
{
$sql = "INSERT INTO user SET
fullname='$fullname',
username='$username',
password='$password',
Email='$Email',
DOB='$DOB',
phonenum='$phonenum' ";

// delete from validate table here and also if $problem = true;

}
else {
echo '<b>Invalid Email</b>';
$problem = true;
}

I also check whether or not the info was inserted into user table corectly etc...
but I get an error saying incorect argument passed to mysql_num_rows ?????? something like that??

Can anyone help?Its wrecking my head?

[zawadi]

you cant use set in an insert statment, you need to write like this:

[code]
INSERT INTO user (
fullname,
username,
password,
Email,
DOB,
phonenum)
values(
'$fullname',
'$username',
'$password',
'$Email',
'$DOB',
'$phonenum')
[/code]

[gk20]

ya it was adding it to tables alright, but just not validating the email entered by the user. I wanted restricted access to certian domains. Anyway got it going in the meantime, thanks all the same