I think, it's too small. Try a bigger value. You can not set grid's height less than column's header height+ a little bit.

>Sorry , I don't know what I am doing wrong :
>
>
>IF THISFORM.grid1.Height = 100
> THISFORM.grid1.Height = 10 <- program stop here
>ELSE
> THISFORM.grid1.Height = 100
>ENDIF
>
>
>VFP7 prompt me error message :
>
>error with grid1 - height : Expression evaluated to an illegal value.
>
>
>What wrong with my program? Try out whole day.... :(
>
>
>TIA.