use this

chance    = 49.95
base      = 0.00000001
prebet    = 0.00000001
nextbet   = prebet
losecount = 0
betcount  = 0
bethigh   = true

function dobet()
   if win then
nextbet = prebet
      chance = 49.95
        losecount = 0
        betcount += 1
bethigh=true
   else
         losecount += 1
betcount = 0

   end
     if (losecount > 0) then
         chance  = 66
         nextbet = previousbet*5
         bethigh = false
bethigh = false
   end
if (losecount > 1) then
    chance  = 75
    nextbet = previousbet*6
    bethigh = true
end
if (losecount > 2) then
chance  = 95
nextbet = previousbet*20
bethigh = false
end
end