[WARNING: SLOPPY CODE AND GLOBAL VARIABLES] bios:366: [string “startup”]:4: ‘then’ expected where "then" would break the code

Here is is, pulled from computercraft.

-- The error I am getting is bios:366: [string “startup”]:4: ‘then’ expected, which really makes no sense there to me.
term.clear()
term.setCursorPos(1,1)
if firstpassrun = " "
then
firstpassrun = "y"
end
if
firstpassrun == y
then
term.setBackroundColor(colors.blue)
print("Welcome to PEX password protection.")
print("Please enter a password!")
systpassword1 = " "
systpassword1 = read()
term.clear()
term.setCursorPos(1,1)
term.setBackroundColor(colors.green)
print("Is this your password:")
print(systpassword1)
print("If this is your password, enter y.")
print("If this is not your password, enter anything else.")
local passconfirm = " "
local passconfirm = read()
if
passconfirm == y
then
term.clear()
term.setCursorPos(1,1)
term.setBackroundColor(colors.blue)
print("Now rebooting to set up password protection, please wait...")
firstpassrun = "n"
os.reboot
else
term.clear()
term.setCursorPos(1,1)
term.setBackroundColor(colors.red)
print("Rebooting. Put in the correct password after reboot, please")
os.reboot
end
else
term.clear()
term.setCursorPos(1,1)
term.setBackroundColor(colors.blue)
print("Protected By PEX. Enter the password, please")
local passrelay = " "
if passrelay ~= systpassword1
then
term.clear()
term.setCursorPos(1,1)
term.setBackroundColor(colors.red)
print("WRONG! REBOOTING!")
os.reboot
else
term.clear()
term.setCursorPos(1,1)
term.setTextColor(colors.cyan)
print("PEXPROTECT-console Version 1")
end
end

This error is covered under the Common Errors section of my favorite sticky post. You've got assignment operators in your if statements instead of comparison operators.