updates opposite to step 1
_two [ 1 ] = ( _two [ 1 ] + 1 ) % size2 ; if ( _two [ 1 ] == 0 ) _two [ 0 ] = ( _two [ 0 ] + 1 ) % size2 ; } else { document . write ( " " + a2 [ _one [ 1 ] ] + " " + a1 [ _one [ 0 ] ] + " " ) ;