IF ALLTRIM(m.DZp) <> "MX" AND m.DZp <> "00000"
		fd=AT(",", m.DCiSt)
		IF fd = 0
			mEr = mEr + nb + "Cannot Determine Destination State"
		ELSE
			mCity = ALLTRIM(LEFT(m.DCiSt,fd-1))
			mState = ALLTRIM(SUBSTR(m.DCiSt,fd+1))
			IF NOT mState $ StStr OR LEN(mCity) < 3 OR m.DCiSt = "Unknown"
				mEr = mEr + nb + "Cannot Determine City, State of Destination"
			ENDIF 
		ENDIF 		
	ENDIF

To me it looks like it's looking for a Mexico address that includes the city and zip code all in one line and parsing/splitting it out if it finds it. I'm having issue figuring how exactly the mEr is called upon, can someone help?