ALTER TABLE .....Error: Must be owner of the table

Hi,

I had created some tables in the schema Foo and given

GRANT ALL ON SCHEMA FOO TO SCOT;

 

But when Scot tries to alter a table he gets the error

MUST BE OWNER OF THE TABLE

 

How can I give the ALTER permission or is there any other way to let other users modify or add tables in this schema?

 

Thanks

Josh