Form validation - invalid characters...

Hello everyone (again),
I'd like to validate a form element and make sure that the user hasn't entered invalid characters. Invalid characters = everything that isn't a to z and 0 to 9.

Any ideas? I found some JS on the web but was unable to convert it and make it work.

Thanks!!

Cheers.

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Comments

Adam Stoller

How about a regex? "^[a-z0-9]+$"

--fish
Senior Consultant, Quotient Inc.
http://www.quotient-inc.com

therocket

That's perfect... Last thing: how do I modify that to allow them to insert "-" and "_"?

therocket

Is this correct?
"^[a-z0-9][\w/_\.][-\w\.]+$"

JonathonG

Assuming you want upper and lower case letters (which the original regex doesn't assume, it only allows lower case letters), the regex becomes simply:

"^[\w-]+$"

\w indicates a word character which is defined to be letters, numbers, and underscores. Then you just need to also include the - character

If you don't want upper case, just add _ and - to the character class:

"^[a-z0-9_-]+$"

Jonathon
Independent Interwoven Contractor

therocket

Perfect! Thanks guys...

Cheers!