try
Code:
/run SendChatMessage(("Casting "..GetSpellLink("Resurrection").." on "..UnitName("target")) or "No Target",GetNumRaidMembers()>0 and "RAID" or GetNumPartyMembers()>0 and "PARTY" or "SAY")
the difference being putting paraenthesis around the entire string so
if (longString..with..concat..UnitName) or "No Target"
so the whole string is all or nothing