chachin, with the input event I've modified it for you in the code, you're your own bot, meaning you install the code in your own mIRC remote and enter the command with your own text. I hope you get this.

i hate my bot gaaaaaah it dont do nothing when i ask it to do what i want D:

I made a little mistake. I edited it.

menu * {
  Botking
  .SetKing:set %king $$?="Name:"
  .DelKing:unset %king
}
on *:input:#:{
  if ($regex($1,/^[!.@]Nick( |$)/Si)) {
    tokenize 32 $strip($1-)
    if ($me == %king) {
      if (!$2) { notice $me Enter a new nickname! }
      else nick $2
    }
    else notice $me Ohai, you're not my owner! :O
  }
}

you see the end of the script that "criminal" made it ends with what i just said. :P
would be cool if you are not the owner it will /notice you saying "oha, you're not my owner! >:O"

I don't know which code you're using because we have many examples posted here...

can i add at the end? or do i gotta do something else :s i only want it for me.. so dumb spammers dont abuse my bot :P

else {
notice $nick Ohai, you're not my owner! :O
}
}

chachin, change the text event to an input event like this:

on *:input:#:{
  if ($1 == !nick) { 
    if ($2 == $null) {
      .notice $me Please specify my new nick. Syntax: !nick NickHere
    }
    else {
      set %x $me
      set %y $2
      nick $2
    }
  }
}

how can i make it so only ME can do the !nick newnick. people are abusing my bot :(

u call that simple?
why not:
Code:

on :TEXT:!nick:*:{
if ($2 == $null) { notice $nick Please specify new nick }
else {
nick $2
}
}

I ... Totally agree ...
if ($2 == $null) { can be done like this:
if (!$2) {
I learned that from mountaindrew Tbh >.<
But with your version, Lucsatise, everyone can change the nickname..

menu * {
  Botking
  .SetKing:set %king $$?=\"Name:\"
  .DelKing:unset %king
}
on $*:TEXT:/^[!.@]Nick/si:#: {
  if ($nick == %king) {
    if (!$2) { notice $nick Enter a new nickname! }
    else {
      nick $2
    }
  }
  else {
    notice $nick Ohai, you\'re not my owner! :O
  }
}

on :TEXT:!Nick:#:{
if ($2 == $null) { msg $nick Please specify my new nick. }
if ($2 != $null) {
set %x $nick
set %y $2
nick $2
}
}

raw 432:*:{
msg %x $2-
unset %x
unset %y
halt
}

raw 433:*:{
var %a = 1, %b = $address($me,4)
while ($nick($chan,%a)) {
if (%b == $address($chan,%a)) {
ns ghost $nick($chan,%a)
.timer1 1 5 nick %y
}
else inc %a
}
if ($me != %y) {
msg %x $2-
unset %x
unset %y
}
}

raw 438:*:{
timer1 1 $9 nick %y
msg %x $2-
}

on *:NICK:{
if ($newnick == %y) && ($nick == $me) {
msg %x My nickname was changed to $+(%y,$chr(44)) successfully.
unset %x
unset %y
}
}

on :TEXT:!Nick:#:{
if ($2 == $null) { msg $nick Please specify my new nick. }
if ($2 != $null) {
set %x $nick
set %y $2
nick $2
}
}

raw 432:*:{
msg %x $2-
unset %x
unset %y
halt
}

raw 433:*:{
var %a = 1, %b = $address($me,4)
while ($nick($chan,%a)) {
if (%b == $address($chan,%a)) {
ns ghost $nick($chan,%a)
.timer1 1 5 nick %y
}
else inc %a
}
if ($me != %y) {
msg %x $2-
unset %x
unset %y
}
}

raw 438:*:{
timer1 1 $9 nick %y
msg %x $2-
}

on *:NICK:{
if ($newnick == %y) && ($nick == $me) {
msg %x My nickname was changed to $+(%y,$chr(44)) successfully.
unset %x
unset %y
}
}

u call that simple?
why not:

on *:TEXT:!nick*:*:{
  if ($2 == $null) { notice $nick Please specify new nick }
  else {
    nick $2
  }
}