Sign up form with regex

Username must be and contain 10 - 20 characters

Email must be a valid address, e.g. me@mydomain.com

Password must alphanumeric (@, _ and - are also allowed) and be 8 - 20 characters

Telephone must be a valid UK telephone number (11 digits)

Slug must contain only lowercase letters, numbers and hyphens and be 8 - 20 characters