NAME
filter_array() - return a selective sub-array
SYNOPSIS
mixed *filter_array( mixed *arr, string fun, object ob, mixed extra );
DESCRIPTION
filter_array() returns an array holding the items of which
passed sucessfully through the function found in object .
The function is called for each element in with that
element as parameter. The second parameter is sent in each
call if given. An object is considered to have passed sucessfully
through (and hence is included in the return array) if
returns 1.
If is not an array, then 0 will be returned.