>i am using the following line of code in my combo box to filter
>out the materials i will be using in my table i call the material
>mat. the line of code i am using in the afterRowColchange of my
>grid:
>lcFilter = [Set Filter To mat="] + mat + ["]
>&lcFilter
>
>This code works fine, and I know how to use the filters
>on tables. I don't understand what the brackets, quote and plus
>[+"] symbols are doing.

Other replies have explained the brackets, so I will just suggest another way of doing this. I would write this:

lcFilterExpression = [MAT="&whatever"]
SET FILTER TO &lcFilterExpression

or better still,

SET FILTER TO MAT="&whatever"

because I do not like &-substituting whole sentences. Of course, if "whatever" was a table field, I would just use

lcFilterExpression = [MAT="] + whatever + ["]
SET FILTER TO &lcFilterExpression