sql - using parameters with max len and check for null vall -

i'm trying count column see max characters. i'm getting warning, know doesn't effect, it's more of annoyance , eliminate warning.
example follows:

declare @countthis varchar (255)  select @counthis = max(len(col1)) #temp  print '------- largest count column-----' + @countthis

the warning receive is:

warning: null value eliminated aggregate or other set operation.

i tried using case statement couldn't figure out. if value null ignore value.

is possible?

you can use

declare @countthis varchar (255)  select @counthis = max(len(isnull(col1,''))) #temp

ANy