newbie: regular expression suggestios

Hi, I am using (getting to grips with) regular expressions for validating form data and have come across a little problem: I have a statement like the following: if (eregi("^[a-z0-9]{strlen($name)}$, $name)) { blah... return true; } , but the strlen($name) does not seem to evaluated. Is there any way this can be accomplished? If the code above is not clear (or correct!), I am returning true iff the input is comprised of chars (letters/numbers) only. Maybe there's a better/more efficient way to accomplish this..? Any information greatly aprpeciated. Thanks in advance! - Best regards, Lee Reilly -- Lee P. Reilly, ms:G758 Szilard Resource, tel:505-665-7025 Bioscience Division, SM-30 Bikini Atoll Rd, Los Alamos National Laboratory, mailto:lreilly@lanl.gov Los Alamos, NM 87545. http://home.lanl.gov/lreilly "Quidquid latine dictum sit, altum viditur"