This is a snippet I made, mostly to get used to dialogs (Which wasnt that hard) and for a few issues in some of my channels.
just right click the channel, find the menu and voila.

Or you can use the alias itself, by typing /chan_flood

If any bugs are found, PM me or post a comment here.

And please, do not ripp or modify this script w/o my permission.

Also, thanks to xDaemon for pointing a few things out.

GL & HF with the script!

Edit:

Made a very quick update, took me 10 minutes to finish, enjoy.

on *:START: {
  if ($version < 6.16) {
    echo -st You are running a version below 6.16 which might cause troubble!
    echo -st I highly advice you to download the newest mIRC client from http://www.mirc.com
    unload -rs " $+ $script $+ "
  }
  else {
    unset $+(%,flood,.%chan)
  }
}
on *:LOAD: {
  if ($version < 6.16) {
    echo -st You are running a version below 6.16 which might cause troubble!
    echo -st I highly advice you to download the newest mIRC client from http://www.mirc.com
    unload -rs " $+ $script $+ "
  }
}
#Channel.flood off
on !*:JOIN:%chan: {
  if (!$nick($chan,$nick,oh)) {
    inc $($+(%,flood,.,%chan))
    if ($($+(%,flood,.,%chan),2) > %c) {
      $+(,.timer,.unset,.flood) 1 %timeout unset $($+(%,flood,.,%chan),2)
      if ($nick($chan,$nick,vr)) {
        msg %chan Join flood detected at $+($asctime(HH:nn),/,$date(mmmm),$chr(32),$ord($date(d))) on %chan $+ .
        msg %chan Locking channel for $duration(%fl.reset) $+ !
        mode %chan +i
        if (!$window(@Flood)) { window @Flood }
        aline -hp @Flood Attempt at join flood was prevent at $+($asctime(HH:nn),/,$date(mmmm),$chr(32),$ord($date(d))) on %chan $+ .
        $+(,.timer,.flood) 1 %fl.reset mode %chan -i
      }
    }
  }
}
on !*:PART:%chan: {
  if ($nick($chan,$nick,vr)) {
    inc $($+(%,flood,.,%chan))
  }
}
#Channel.flood end
alias flood_info {
  echo -at The current settings are:
  $iif(%chan,echo -at Channel: %chan, echo -at No present settings for the channel!)
  $iif(%timeout,echo -at Timeout: $duration(%timeout), echo -at No present settings for the timeout!) 
  $iif(%fl.reset, echo -at Reset time: $duration(%fl.reset), echo -at No present settings for the reset time!) 
  $iif(%c,echo -at Max join/parts: %c, echo -at No present settings for maximum join/part!) 
}

alias flood_reset {
  set %timeout 30
  set %fl.reset 20
  set %chan #none
  set %c 5
  echo -at Everything was reset!
}

dialog chan_flood {
  title "Channel flood control v.1.17 by: Lindrian"
  Size -1 -1 260 285
  box " Channel [Only works in one channel!]  ", 1, 15 10 225 45
  edit # $+ %chan, 2, 26 26 202 20, tab 100
  box "Timeout", 3, 15 60 225 45
  edit $duration(%timeout), 4, 26 75 202 20, tab 100
  box "Reset time", 5, 15 110 225 45
  edit $duration(%fl.reset), 6, 26 125 202 20, tab 100
  box "Maximum join/parts [Must be a number!]", 7, 15 160 225 45
  edit %c, 8, 26 175 202 20
  button "Ok", 9, 85 210 55 20, ok
  button "Cancel", 10, 20 210 55 20, cancel
  button "Reset", 11, 20 230 55 20
  button "Settings", 15, 85 230 55 20
  button "Enable", 13, 20 250 55 20
  Text "Channel Flood protection v.1.17 by Lindrian - Locks the channel on eventual flood!", 12, 145 210 100 180
}

alias chan_flood { if (!$dialog(chan_flood)) { dialog -m chan_flood chan_flood } }

on *:dialog:chan_flood:*:*: {
  if ($devent == init) {
    did -ra $dname 2 $iif(%chan,%chan,-No settings-)
    did -ra $dname 4 $iif(%timeout,$duration(%timeout),-No settings-)
    did -ra $dname 6 $iif(%fl.reset,$duration(%fl.reset),-No settings-)
    did -ra $dname 8 $iif(%c,%c,-No settings-)
    $iif($group(#channel.flood) == on,did -ra $dname 13 Disable,did -ra $dname 13 Enable)
  }
  elseif ($devent == sclick) {
    if ($did == 15) {
      flood_info
    }
    elseif ($did == 13) {
      $iif($group(#channel.flood) == on,disable #channel.flood,enable #channel.flood)
      $iif($group(#channel.flood) == on,did -ra $dname 13 Disable,did -ra $dname 13 Enable)
    }
    elseif ($did == 11) {
      beep 2 | var %warn $input(Are you sure you wish to reset to default settings?,yv,Warning - Flood protection)
      if (%warn == $no) { return }
      if (%warn == $yes) {
        flood_reset 
      }
    }
  }
  elseif ($devent == edit) {
    if ($did == 2) {
      set %chan $did(2) 
    }
  }
  elseif ($did == 4) {
    if ($did(4) isnum) {
      set %timeout $did(4)
    }
    else {
      beep 2 | var %error $input(You did not input a correct value in the edit box!
    }
  }
  elseif ($did == 6) {
    if ($did(6) isnum) {
      set %fl.reset $did(6)
    }
    else {
      beep 2 | var %error $input(You did not input a correct value in the edit box!
    }
  }
  elseif ($did == 8) {
    $iif($left($did(8),1) != $chr(35),set %c $+($chr(35),$did(8)),set %c $did(8))
  }
}

menu * {
  -
  Flood prot
  .Flood protection: chan_flood
  .-
  .Credits!: echo -at Channel protection by Lindrian! v.1.17 | echo -at Contact me through irc.deltaanime.net @ #Lindrian or #L2forever! Also join me at: irc.ungowa.org @ #Ungowa!
  -
}
menu @flood {
  .Clear @Flood: var %con $input(Are you sure you wish to clear the window?,yv,Confirm - Flood protection) | if (%con == $yes) { clear @flood }
}