What's
PROCESS_BAU[$id_type]? Did you mean to use
$PROCESS_BAU[$id_type] instead?
btw, to embed php arrays within string, you need to either use a syntax like
PHP Code:
echo "some".$myartay['some_index']."string";
or
PHP Code:
echo "some {$myartay['some_index']} string";
. I'd prefer the second one.