If you run the little code snippet below it will not give you the results you expect. However, in proc secprg if you change x and y to m.x and m.y, you will get the desire results. This VFP behavior just bit me in the *** big time when I added a field to a table in an application and was dismayed to be alerted by uses that a part of my program which had worked flawlessly for years suddenly was broken.

Clear
Create Table test Free (x n(1),y n(1))
Use test
Append blank
Replace x With 3
Replace y With 5
?x
?y
Do secprg
?x
?y
Use In test
Delete File test.dbf

****************
Procedure secprg
local x,y
x='a'
y='b'
?x
?y