I am trying to simulate the D-flop that is in this website.

http://www.designers-guide.org/VerilogAMS/functional-blocks/dff/dff.va

I am getting error msg: . Help appreciated...thx.

ncelab: *E,CUVDNF (/test/dflop_tb/schematic/verilog.vams,17|15): Could not determine discipline for this expression .
qb ), .q( q ), .d( d ) );
                  |

Here is my testbench:
`include "disciplines.vams"

module dflop_tb ( qb,q,d );

output   qb;
output   q;
input   d;



dff1 (*
integer library_binding = "test";
*)
I2 ( .clk( net13 ), .qb(
qb ), .q( q ), .d( d ) );

vsource #(.delay(5u), .type("pulse"), .period(500p), .width(250p), .edgetype("linear"),
.val0(0.0), .dc(0), .rise(50p), .val1(1), .fall(50p)) (*
integer
library_binding = "analogLib";
*)