how do I pass & retrun an array to form

In addition to what the others have told you, I like to have a class whose sole purpose is to return arrays in an object property like so:

DEFINE CLASS xparameters AS line
  Height = 17
  Width = 100
  Name = "xparameters"

  *-- An array to hold the return values
  DIMENSION aparameters[1]

  PROCEDURE Init
    LPARAMETERS taArray
    ACOPY(taArray, This.aParameters)
  ENDPROC
ENDDEFINE

Then, to return an array, you just use code like this:

RETURN CREATEOBJECT( 'xParameters', @laArray )