avoid username registration field with blank spaces
hi, i have noticed that in 3.0.5.1 when registering for a new account or posting and registering, username field can be anything including Spaces between the words. and i have seen users always have problems in all my websites when trying to login later because they never remember they left a blanck space between their username letters or words. How can we control the username field to accept only words and letters with No blank spaces ?