i think this works

chance=80
profittarget=0.1
function dobet()
if win then
nextbet=0.0000001
else
nextbet=previousbet*10
end
if currentstreak == -3  then
nextbet=balance/100
end
if (balance) >= profittarget then
stop();
print(balance)
print("TARGET ACHIEVED!!!")
end
end
end