Simon Moses Qs

dear sir,
i am using postgresql 7.2.
i want to concatenate 'character varying' and 'boolean' ex.
select character_varying_field||boolean_field as new_field from table_name;
or any function to convert 'boolean' to 'character varying' so that i can use
select character_varying_field||convert_function(boolean_field) as new_field from table_name;
thanks in advance
simon moses.