Only adults 18+ can register

[youradultworld]

Hi, my website youradultworld.com will be an adult site that only adults 18 and over can register on. I found a post that said to replace the two occurences of the age '13' in register.php with the age you want to be the minimum. I did this and in admincp enabled the option that disallows registration to anyone younger than 13 I believe.

When someone tries to 'register' they are prompted first for their date of birth, if they select something younger than 18 it tells them that they must be atleast 18, but if they enter a birthdate such as 1980 for example, registration progresses to step two, which asks for username, password, email, date of birth (again), etc.

During the 2nd part of registration when it asks for your birthdate again, no matter what I enter for birth year, it says registration is complete, but at the top left of the screen it gives an error message:

Warning: Compilation failed: missing ) at offset 30 in /home/youradul/public_html/register.php on line 437

When I replace the two occurrences of '18' back with 13, I don't seem to get the error message.

This is a very important yet basic modification needed by me, if someone would help me with this I would greatly appreciate it.

Thanks in advance.

-Chris