When posting code please use the Code Tags. You have a habit of using the Quote tags instead. The Code tags are just to the right of the Quote tags.

I did a bit of fixing up of your code, and this should work properly.
Code:
 on *:text:!login & &:?: { 
  if ($($+(%,password.,$2),2) == $2) {
    set $+(%,loggedin.,$nick) yes
    notice $nick You logged in successfully!
  } 
  else { notice $nick Wrong password. } 
} 
on *:text:!password & &:?: { 
  if ($($+(%,loggedin.,$nick),2) == yes) {
    set $+(%,passw0rd.,$2) $3
    notice $nick Password for $2 changed to $3 $+ .
  } 
  else { notice $nick You are not logged in. Please log in. Don't have an account? You dont have access. } 
}


Most likely one question that will occur to you is "what happened to the *?"
I'll answer that now, I replaced them with & which is another wildcard character, but & only matches one word, as * will match any number of words (including none)

If you have any other questions, ask and I'll do my best to explain.