for case-insensitive search, using character sets with the pattern/regex might work
Code:
if strfind(yourmsg, "[Dd][Rr][Uu][Ii][Dd] [Tt][Aa][Nn][Kk]") then
-- do stuff
end
but yes, if people make typos it wont work ..
-- Edit:
NitraMo is right;
Myself, I'm way to accustomed with using character sets for in string.gsubs ;(