Gerard
I've been using ChartFX for that last year in our new product (VFP8 with SQL Server for the backend) and I love it. It works, it's simple and it has a GREAT help file that comes with it. It's not free and I think it was about 295 USD, but I feel that it is worth it. I used to use t-chart and it worked, but it seemed cluncky to figure out.
Kirk