how to check SQLSTATE

Hi,

is it possible to check for sqlstate inside a function , something like:
....
loop
fetch bla.....
if sqlstate = '02000' then
exit;
end if;
....
end loop;
if I try to save the above I get a : sqlstate not defined error

Then I tried this with no success:

....
loop
Begin
fetch bla.....
Exception
when no_data then
exit;
end;
....
end loop;
when I tried to save the trigger I got this: unrecognized exception
condition "no_data"
but according to the help docs, no_data is a valid symbol.

could anybody give me some hints

thanks

Hugo