You can redim multidimensional arrays  as well.....
If you use the keyword redim, all existing data in the
array would be deleted. to avoid this use the keywords
"redim preserve"

Illus:

REDIM TEST(5,5) AS STRING ' would reset dimension but
delete existing contents of TEST

REDIM PRESERVE TEST(5,5) AS STRING ' would not only
reset the dimension but also retain existing contents
of TEST.