function Request()

  if hc.method == 'GET' then

    ims = hc_ims

      if ims~=nil then
        hc.action = 'dont_update-'
        hc.monitor_string = hc.monitor_string..'ims to don't update '
      end 

  end

end

Those vars belong to hc table, thus you have to refer to them as hc.hc_ims and hc.request_ims in your code.

04.01.13 20:08:02,297 # 157: Start connection from client

04.01.13 20:08:02,297 # 157: Connection from 127.0.0.1:3163 to HC Version 1.00 RC3 (1.0.0.408)

04.01.13 20:08:02,297 # 157: User name: local

04.01.13 20:08:02,297 # 157 <<< URL: http://giantmug.com/jengchein/Popcap/Popcap%20Alchemy%20Deluxe.exe
BRHS-SCRIPT "Request" ERROR:
[string "?"]:20: '=' expected near 'update'

Why don't you look up the Lua reference, btw?

function Request()

  if hc.method == 'GET' then

   ims = hc.hc_ims

      if ims~=nil then
        hc.action = 'dont_update-'
        hc.monitor_string = hc.monitor_string..'ims to don\'t update'
      end 

  end
end