diff --git a/client/scripts/mifareplus.lua b/client/scripts/mifareplus.lua
index fbc374d72..b4e274c99 100644
--- a/client/scripts/mifareplus.lua
+++ b/client/scripts/mifareplus.lua
@@ -67,19 +67,19 @@ function writePerso()
 	--		0x0C - unexpected command length
 	
 
-	-- First, set all the data in the card (4kB of data) to zeros. The keys, stored in the sector trailer block, are also set to zeros.
-	-- The only block which cannot be explicitly set is block 0x0000, the manufacturer block.
-	print("Setting values of normal blocks")
-	for i=1,255,1 do --skip block 0
-		--convert the number to hex with leading zeros, then use it as the block number in writeBlock()
-		blocknum = string.format("%04x", i)
-		writeBlock(blocknum, SIXTEEN_BYTES_ZEROS)
-	end
-	print("Finished setting values of normal blocks")
 
+	cardsize = 4 --need to set to 4 for 4k or 2 for 2k
+	if(cardsize == 4) then
+		numsectors = 39
+	elseif(cardsize == 2) then
+		numsectors = 31
+	else
+		oops("Invalid card size")
+	end
+
+	-- Write to the AES sector keys
 	print("Setting AES Sector keys")
-	-- Next, write to the AES sector keys
-	for i=0,39 do --for each sector number
+	for i=0,numsectors do --for each sector number
 		local keyA_block = "40" .. string.format("%02x", i * 2)
 		local keyB_block = "40" .. string.format("%02x", (i * 2) + 1)
 		--Can also calculate the keys fancily to make them unique, if desired
@@ -153,9 +153,9 @@ function getVersion()
 	sendRaw(GETVERS_CONT, true, true)
 end
 
-function commitPerso()
-	-- commandString = COMMITPERSO .. "01" --switch to SL1
-	commandString = COMMITPERSO .. "03" --switch to SL3
+function commitPerso(SL)
+	--pass SL as "01" to move to SL1 or "03" to move to SL3.
+	commandString = COMMITPERSO .. SL
 	response = sendRaw(commandString, true, true) --0x90 is returned upon success
 	if string.sub(response, 3, 4) ~= "90" then
 		oops("error occurred while trying to switch security level")
@@ -205,9 +205,20 @@ function proximityCheck()
 
 	--PC--
 	RndC = "0001020304050607" --Random Challenge
-	commandString = PROXIMITYCHECK .. "08" .. RndC
-	response = sendRaw(commandString, true, true)
-	RndR = string.sub(response, 3, 18)
+	num_rounds = 8 --Needs to be 1, 2, 4, or 8
+	part_len = 8 / num_rounds
+	j = 1
+	RndR = ""
+	for i = 1,num_rounds do
+		pRndC = ""
+		for q = 1,(part_len*2) do
+			pRndC = pRndC .. string.sub(RndC,j,j)
+			j = j + 1
+		end
+		commandString = PROXIMITYCHECK .. "0" .. tostring(part_len) .. pRndC
+		pRndR = string.sub(sendRaw(commandString, true, true), 3, 3+part_len)
+		RndR = RndR .. pRndR
+	end
 	print("RndC = " .. RndC .. " RndR = " .. RndR)
 
 	--VerifyPC--
@@ -245,8 +256,14 @@ function main(args)
 	-- Initialize the card using the already-present read14a library
 	info,err = lib14a.read14443a(true, false)
 	--Perform PPS (Protocol and Parameter Selection) check to finish the ISO 14443-4 protocol.
-	sendRaw("e050", true, true)
-	sendRaw("D01100", true, true)
+	response = sendRaw("e050", true, true)
+	if(response == nil) then
+		err = "No response from RATS"
+	end
+	response = sendRaw("D01100", true, true)
+	if(response == nil) then
+		err = "No response from PPS check"
+	end
 	if err then
 		oops(err)
 	else
@@ -257,7 +274,7 @@ function main(args)
 	-- Now, the card is initialized and we can do more interesting things.
 
 	--writePerso()
-	--commitPerso()
+	--commitPerso("03") --move to SL3
 	--getVersion()
 	proximityCheck()
 
@@ -278,4 +295,4 @@ function main(args)
 
 end
 
-main(args) -- Call the main function
\ No newline at end of file
+main(args) -- Call the main function