Please see my reply to John.
Thanks.

>SWAG Alias()# "V_Work"
>
>untested

>IF !EMPTY( this.control_source )
>       local lcAlias, lcField, lSource
>       lcSource = ALLTRIM(this.control_source)
>	lcAlias = Left( m.lcSource), AT('.', m.lcSource) - 1)
>       lcField = Subst( m.lcSource), AT('.', m.lcSource) + 1)
>	IF SELECT( m.lcAlias ) > 0
>		IF EVALUATE( m.lcSource) == OLDVAL( m.lcField, m.lcAlias )		
>			RETURN .T.
>		ENDIF 
>      ENDIF
>ENDIF

>
>V_WORK.EMPLOYEE
>>>
>>>The code then checks is the value of the field EMPLOYEE in the cursor V_WORK has been change. Here is the code:
>>>
>>>

>>>		cControlSource = ALLTRIM( this.control_source )
>>>		IF EVALUATE( cControlSource ) == OLDVAL( cControlSource )		
>>>			RETURN .T.
>>>		ENDIF 
>>>

>>>
>>>The problem occurs on the line above, EVALUATE( cControlSource ) == OLDVAL( cControlSource ), and it does
>>>ALIAS IS NOT FOUND. I verified that the entry in .control_source exists as described above.
>>>
>>>TIA.
>>>
>>>UPDATE. the following code checks that the alias V_WORK exist and is open. This code, below, is before the code above (just in case someone wonders if the alias is indeed exists and open
>>>

>>>
>>>IF !EMPTY( this.control_source )
>>>	cAlias = SUBSTR( ALLTRIM(this.control_source), 1, AT('.',ALLTRIM(this.control_source)) - 1)
>>>	IF SELECT( cAlias ) > 0
>>>		cControlSource = ALLTRIM( this.control_source )
>>>		IF EVALUATE( cControlSource ) == OLDVAL( cControlSource )		
>>>			RETURN .T.
>>>		ENDIF 
>>>      ENDIF
>>>ENDIF
>>>

>>
>>I added - for testing - a TRY / CATCH around the above code. Then modified the line:
>>

>>cControlSource = ALLTRIM( this.control_source )
>>

>>to a bogus:
>>

>>cControlSource = "test.test_field" 
>>

>>
>>And the error caught by the TRY / CATCH, says "Alias 'test' not found".
>>But the error that the customer saw (without a TRY /CATCH) did not have the "bad" alias name. It was simply:
>>ALIAS IS NOT FOUND
>>
>>Any suggestions?