A form using regular expressions
Username must be alphanumeric and contain 5 - 12 characters
Email must be a valid address, i.e. me@mydomain.com
Password must be alphanumeric (@, _ and - are also allowed) and be 8 - 20 characters
Telephone number must be a valid UK telephone number (11 digits)
Slug must contain only lowercase letters, numbers and hyphens and be 8 - 20 characters