You'd have to do something like:
Code:
if sender == UnitName("party1") then
To check for a certain word in a string you need to use
strfind:
Code:
if strfind(strlower(msg), "blizzard") then
You'll probably want to use strlower or strupper on msg, like I did in the example, so that you can search for a pattern regardless of upper and lower case.