I am currently using this:
This does not permit a space within the username.
However, I want to allow a single space within the username but not allow multiple spaces.
John Doe - should be valid - as should John F Doe - i.e. a space between each word.
John.......Doe is invalid as it has multiple intervening spaces - shown here as dots as I cannot enter white space.
Can anybody help a I am suffering from a brain freeze with regex.