Dynamically set Visibility of fields

Visibility of fields As we use set_item_property in forms 6i to set a the visibility property of a particular field true or false,

How can I do the same thing in the reports 6i? i.e dynamically setting the visibility property of a particular field true or false...

First select the field and right click and select plsql Editor and
write the condition ,if condition is satisfied then return true other wise return
false .
for example
function F_SALFormatTrigger return boolean is
begin
if (condition) then
return (TRUE);
else
return (false);
end if;
end;