Priority against catalog

I created a function called Version(),
The same that there is in PostGreSQL Catalog.

But, to call this function I'm obrigated to
specific the SCHEMA.Version. I would like it
execute my functions when I don't to specific
the SCHEMA.

I would like the PostGreSQL give priority to my
function and classes when they exists, of course.

This function is just a example. But I also need
to created operations that I would like to subscrive.

Thanks,

Cristian