icircuits has a few flaws,the n chanel and the p chanel jfet transistor s symbols laks a gate a drain and a source and its not acurate,try this experiment pleas 5vdc as a source of power,conect drain lead of the n chanel jfet to + of the 5v power source and the source lead to to the - of the 5v power supply and short the gate to the - of the power source and click on of the simulated wire and see the results its lik theirs no short cuit at all between the gat and the source,i tryed various valu of reistance and its the the sam result,i tryed a p chanel jfet,of cource i reversed the polairity of the power supply and for the pchanal of the other jfet and the results