[Csnd-dev] two dimensional arrays

What is the syntax to address a two d array>  I have

ginst[] init 3,8
...
if ginst[p1,p5] != 0 then
  turoff ginst[p1,51
  ginst[p1,51 nstance
endif

but the parser says

error: syntax error, unexpected ','  (token ",")
 from file bbb.csd (1), line 43:
 >>> if ginst[p1, <<<
Parsing failed due to invalid input!

Or is this only in an if?

==John ffitch