[Amplitude]=SquarePulse(t)

function [Amplitude]=SquarePulse(t)
%Input
%   t          (us)
%Output
%   Amplitude  (uA)
%   setting the Amplitude to empty indicates the end of the stimulus
%   pulse. This helps speed up the calculation
%----------------------------------------
Pulsewidth  =   500;    %us
Delay       =   0;      %us
Amp         =   -0.1;   %uA  %for Iinstim
%Amp         =  -200;    %uA  %for Iexstim
%----------------------------------------

if t<=Delay
    Amplitude=0;
elseif t <= (Delay+Pulsewidth)
    Amplitude=Amp;
else
    Amplitude=[];
end