help on start with and connect by with parameter

I'm doing a tree that can take a parameter. The parameter is the father #. Because I want to let the user have the choice of seeing the whole tree or part of the tree depending on the parameter the user had chosen.
E.g. if the user enter 1 the function will only show this tree part with all his children, but if the user enter 0, it will show the whole tree.

This is the syntax that i'm using

select child
FROM tableX
START WITH (father) = &akey or &akey=0
CONNECT BY father = PRIOR child

Without the &akey=0, it's working. But with the 0, it doesn't show anything.

Please help me. Thanks Received on Wed Dec 05 2001 - 10:26:39 CST