UBOUND

[bartok]

DIM X(1) is an array with one element.
DIM X is a variable.

SUB foo(x, y() )

Now, in that SUB, what values can you pass to those parameters?
For x, you pass a single value, or a variable.
Your y(), you pass a whole array.

A variable is NOT the same as a single element array.

Variables can never be REDIMed to hold more elements.  They have no indexes.  The contain just a single value.  

Even a single-element array has an index.  X(0).  This index tells you, "THIS IS NOT A VARIABLE."  Don't fool yourself into thinking it is.

Ok, It's clear. Thank's!