UNC Create User Shell Script Mac

#!/bin/sh
#This script works with the gui based applescript which prompts for onyen account details
#This script requires three arguments - 1st: onyen ID - 2nd: onyen Password - 3rd: uncsupport password suffix

NewName=$1
Password=$2
echo setting computer name
scutil --set ComputerName "${NewName}'s Computer"
echo setting local name
scutil --set LocalHostName $NewName
#echo setting host name
#scutil --set HostName $NewName

#Get random number between 510 - 1000 to use for UniqueID
High=1000
Low=510
number=0   #initialize
while [ "$number" -le $Low ]
do
  number=$RANDOM
  let "number %= $High"  # Scales $number down within $RANGE.
done

#create onyen account
dscl . -create '/Users/'$NewName
dscl . -create '/Users/'$NewName UserShell /bin/bash
dscl . -create '/Users/'$NewName RealName "$NewName"
dscl . -create '/Users/'$NewName UniqueID $number
dscl . -create '/Users/'$NewName PrimaryGroupID 20
dscl . -create '/Users/'$NewName NFSHomeDirectory /Users/$NewName
dscl . -create '/Users/'$NewName AuthenticationHint "Call 962-HELP"
dscl . -passwd '/Users/'$NewName $Password
dscl . -append /Groups/admin GroupMembership "$NewName"

#Disable autologin
defaults delete /Library/Preferences/com.apple.loginwindow autoLoginUser

#setup UNC Support Password Algorithm
serialnumber=`ioreg -l | grep IOPlatformSerialNumber|awk '{print $4}' | cut -d \" -f 2`
suffix=$3
algorithm=${serialnumber:(-5)}$suffix

#Change UNC Support password
dscl . -passwd '/Users/'uncsupport $algorithm

#Hide UNC Support Account
defaults write /Library/Preferences/com.apple.loginwindow Hide500Users -bool TRUE
defaults write /Library/Preferences/com.apple.loginwindow HiddenUsersList -array 'UNCSupport'

#restart computer
shutdown -r now