using update command under a_output

[Anon]

Dear friends,
can any one help me.

situation is like this postgresql database:-
Throuth the function i have to update the
boolean column in a table.
Generally update command will be like this
Update tablename set
Booleancolumn = \'value\';
In the function i am storing this command
a_output:=
\\'Update tablename set booleancolumn=\\'
||\\'InsertCValueBool\\'||\\'\\'\\'\\' ;
when i print the a_output it is like this
a_output=update tablename set
booleancolumn =\'InsertCValueBool\';
Instead of placing the value holded by the variable it is placing the variable.
thanks in advance.
your Suman.([e-mail])