NP Cheers :)

eww - didn't see that. Thanks.

Just because you have the correct amount of brackets overall, doesn't mean that your brackets are correct. All mirc does is count them.

on *:INVITE:*: { if (!%flood.protect) {
  .timer.invite 1 1 invited 
  set %invite.chan $chan
  set %invite.nick $nick
  set -u5 %flood.protect
}

Where is the second closing bracket in this event ?
This event is not closed until the end of the invited alias, putting the invited alias inside of the on invite event.
No way this work correctly ;/

It still works... And There isn't a bracket mismatch (mIRC didn't say there was an error)

You have a bracket mismatch in the on invite event and the else statement is on the outside of the alias invited.

flood protection added - fixed title

You are very correct Spanky. Giving someone the power to open a window on your computer should be done with more caution than any other script. The result of an invite flood on this script would be your computer crashing.
Iron Clad flood protection for this script is a must, as it creates a major exploit.

 ;###############################
;Created by PwnerJohn          #
;Helped by IE|ix007 (GameSurge)#
;###############################

on *:INVITE:*: { 
  .timer.invite 1 1 invited 
  set %invite.chan $chan
  set %invite.nick $nick
}

alias invited { 
  if ($?!="You have been invited to %invite.chan by %invite.nick Accept or Deny?" == $true) { .j %invite.chan  
else { .msg %invite.nick I do not want to join that channel at this time. Thanks for the invite though! | unset %invite.chan | unset %invite.nick } }
   unset %invite.chan
  unset %invite.nick
} 

oh and maybe, if they keep inviting you even you said no make it ignore them. just a few ideas.

Looks like you've got an issue with your title here.

The else { } is outside of the alias invited.

btw some mircs dont have the J alias to join rooms so your better of using Join,

Edited.

think about adding when you accept to auto join the channel. and when you deny to notice/msg the inviter you dont want to join the channel.