How would you create a SQL Statement to alter a table in SQL Server 2008 to add an additonal column?

How would you create a SQL Statement to alter a table in SQL Server 2008 to add an additonal column?

I tried the following SQL Statement:

ALTER TABLE tblFlINT ADD ActiveRecord boolean;

Which created the following error:

Msg 2715, Level 16, State 7, Line 1
Column, parameter, or variable #57: Cannot find data type boolean.

I also tried:

ALTER TABLE tblFlINT ADD ActiveRecord bool;

Msg 2715, Level 16, State 7, Line 1
Column, parameter, or variable #57: Cannot find data type bool.