Dereferencing a 2-dimensional array in plpgsql

I am having an issue with trying to dereference a 2-dimensional array in
plpgsql. The idea is to have an setup like:

DECLARE
myarray varchar[][];
myvar    char;
BEGIN
--stuff
myarray[1] := ''{value1,value2,value3}'';
myarray[2] := ''{valuea,valueb,valuec}'';

--If I then:

myvar := array[1][1];

--I get a subscript error generated. I have tried everycombination of
array[1:1][1], etc all to no avail.

I have also tried pre-initializing myarray with
myarray := ''{{}}'';

The docs seem to to indicate that a simple myarray[1][2] for example
should work, but that does not hold true in the plpgsql. Is there
another type of initialization that is needed to be done? Any advice?

Sven