function [ return_value ] = testfunc( string1, string2, k, st )
%TESTFUNC Summary of this function goes here
%   Detailed explanation goes here
%string1
y = 0;
if strcmp(string1,'Call')
    if strcmp(string2,'Short')
     y = -max(st-k,0); 
    else
     y = max(st-k,0);
    end
    display ('Call')
elseif strcmp(string1,'Put')
    if strcmp(string2,'Short')
     y = -max(k-st,0); 
    else
     y = max(k-st,0);
    end
    display ('put')
elseif strcmp(string1,'Stock')
    if strcmp(string2,'Short')
     y = -st; 
    else
     y = st;
    end
    display ('stock')
elseif strcmp(string1,'Bond')
    if strcmp(string2,'Short')
     y = -k; 
    else
     y = k;
    end
    display('bond')
end

return_value = y;

end

