[FX.php List] User exists - offer other names

[William Downs]

Hi guys,

I'm looking for something here and have no idea where to start !

I am building a DB where a user can enter themselves - contact data
and user name.
I am looking for a way to say "This user name is already taken. Please
enter another name"

This I can do - what I CANNOT do is offer them a selection of names (5
possibilities) that also do not exist !

Example entered:
User name = wills
Returns:
This user name is already taken. Please enter another name. Possible
examples are
wills100
wills200
wills300
wills101
wills202
Or enter an entirely new name.

Of course, none of the above 5 names exist either.

Any ideas ?

William