countdown timer not appearing on screen (case 12356)

[Nick00004]

Hello,

I need a 5 minute (300 seconds) countdown timer for an essay response. I've tried to embed it in the exp file (i.e., parameter set at (d-300)), but for some reason it's still not appearing on the screen. I've looked at other threads but can't seem to figure out the reason why this might be so.

Any help would be much appreciated.

Cheers,

Nick